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					                                        The                         Immobilizing                                                                Efficiency                                           of Back                                    Braces                               t
                             THLIII                   EFFECT                         ON           THE                POSTURE                           AND          MOTION                           OF      THE              LUMBO5ACnIAL                                   SPINE

                 liv          PAUL                   L.        NORTON,                           M.D.,               AND               THORNTON                           BROWN,                       M.D.,               BOSTON,                    MASSACHUSETTS

                                                                From           the          ()rthopaedic                          Service,                Massachusetts                         General              Hospital,                  Boston


                 Supportive                                    apparatus                               in the               form                of braces,                     plaster-of-Paris                                       jackets,                 corsets,                  and          belts
  are           tnsed                  extensively                             inn        the                treatment                        of low-i)ack     disabilities.   It is usually      assumed      that
  such             apparatus                                   has           ann       immobilizing                                       effect.    Certainly      the braces    worn   following       spine   fu-
  sionn           are                  prescribed                             with                this               purpose                       in         mind.              However,                             some               apparatus,                              notably                  the
  Goldthwait                                   and             Williams                           braces,                    fall          into              a different                       category,                         since            they              are          employed                     to
  correct                     excessive                             lumbar                      lordosis.                         In spite                    of the             wide                use          of back                    supports                      anid          the         great
  finrancial                           outlay                  for          sri(h               apparatus,                               little              is really                   known                    of their                   friniction.
                 For               centuries,                              supports                           have                been             worn             by         persons                      with            gross             spinal                deformities                          dire
 to         Pott-’s                     disease                      and            scoliosis’.                            Indeed                      many               of        the              i)races               now              employed                         for         low-hack
 paini            were                  origitnally                          designed                          for         the            treatment                        of spinal                       tuberculosis,                             so that                 the         purposes
 for            which                     they                 are           nnois’ being                             used                are             quite           different                         from               those               for         vhich                 they             ‘ere
                 Although                             all           supports                           for      the            1)ack,               regardless                      of design,                          are         constructed                            on the              prinnci-
 plc            of three-point                                       pressure,                          the          effecti\’enlesS                              of the                 forces              thus             developed                         will         vary              connsid-
 erahlv.                     Inn essence                              there               are                two        couniterforces                                  applied                      by the                upper                and           lower               ends          of the
 apparatus                                and             a third,                        corrective                              force                is located                    between                         these.                 With              a hyperextennsionr
 brace,                     the              corrective                        force                    is     applied                      posteriorly,                            while                  with             the          Williams                         lordosis                   brace
 tilis           force                  is      apphe(l                       anteriorly                              to          the          abdomen.                         Obviously,                               in those                    braces                iii       which               the
 (orrecti\’e                              force                is      Iocate(l                        essenrtially                            nlid\vay                   between                          the          other               two          forces,                  the        mecha-
 nnisrn           is neasonnai)ly                                     efficient.                         However,                          if this              force            is tobe                   applied                    to the          lumbosacral                              regiorr,
tile            lower                   or       l)elvic                   lever            arm                is markedly                                   shortened.                         Since               fixation                   to the                pelvis              is made-
(Innate at  l)est,                                    the              middle                     or          corrective                           force            must                 under                   these              circumstances                                 he      reduced
                 ‘The                  purpose                       of this                     study                  i’as              to        determine                            as      accurately                            as       possible                 the effect     of
i)ack             supports                            on             the       movement                                    arid            posture                     of the                 lumbosacral                              spine.              As         the study     pro-
gressed,                          a somevhat                                  different                             concept                     in back-bracing                                       was            evolved,                      which               culminated       inn
the             development-                                        of a mew                      brace                designed      to give better     lumbosacral                                                                              immobilization.                                      This
brace                  is         nnoi’           being                    tested                 botil               experimentally        arid clinically.      This                                                                          presentation                             is a pre-
liminiarv                          report                 of progress.


            No          attdflil)t                   was             tirade          to         test          all     of       the         low-back                 su)perts                    winicin             have         i)een          (lescribed.                 Representative
ap)aratus                         in      (oninlon                    mine     \s(re             selected.                   The           braces             and         corset-s              were             made          in      the        i)raee        shop             of the         Iassa-
(inusettS                   General                  Hospital                  arid          were              fitted             as     carefully                as 1xssihle.                       The         plaster-of-Paris                          ja(kets               i’ere      niade          by
tine      authors.                      Tine         JeW(’tt                 an(h         \Vihhiams                     braces                 i’ere         purchased                    from             the manufacturers                                  and         carefully              fitted.
            Tine             i)n’a(’es            teste(1              in(’lll(le(l                tine         tioldt-inwait,                         the     Taylor               of        both          rigid          and         flexible            (‘onstruction                     (Fig.         I),
tine      Arnol(i-Abl)ott                                 (Fig.            2), the              Jeivett,                the chair-back                            (Fig.         3), arid the Williams                                    braces.              The         study,          therefore,
iin(’ill(le(l               exanil)l(s                    of        short           and            long             sul)1)orts,                   1)0th        with           and         without                   thoracic                i)an(15           and         lateral          11)rightS.
             Tests             were   l)erforni((I                             011 sui)jects                          ivitin           clinically              normal               spines                aind       no       i)ack          h)ain       or     nius(le             spasm.             Tinis
was         tionne           in order      to ensure                                 that              the      effects                of weaning                   the        i)ra(’e,          what-ever                    tiie’         niight            be, were              attril)utai)le

            *    ‘l’his            investigation                            was           su)porte(1                       l).’        contract               Xo.         V     1001             \I-1766                with          the       Veterans                   Adnninustration,
Project                No.             756.4)01             1-5.
      t Based                           OIl a paper                         read           at          the          Annual                Meeting                 of      The            American                    Academy                    of Orthopaednc                           Surgeons,
I_40s Angeles,                           California,                       February                      2, 1955.
VOL.        39-A.             NO.            1. JANUARY                       1957                                                                                                                                                                                                                       111
112                                                                                       P.      L.       NORTON                   AND          THORNTON                             BROWN

to    the     apparatus                    and         riot        to    other                  factors.             It must             be     admitted                 that          the      action                of the          braces          tinder            these              cir-
(‘lnITiStItiI(’eS             iiia,v       well         be quite                        different               from         that         in     the        ease         of      a patient                    with           back         pain        arid        tenderness.
            The       snihjents                were            males,                   rariging             in       age     from             twenty-three                      to          fifty-one                 years.          They           represent-ed                         the
common               body          t’J)(5           aiid         rairged                 in height                   from      five feet,              eight        inches,                to six feet,                    two      inches.           One         was             moder-
nntel’ StOUt.
            As a      first       Stel),         the          slll)je(’tS                were           siflhl)13’      oi)served               as they            wore              the      various                 strpports.            The        behavior                      of the
ap)aratus                wit-h         tint’        stlh)je(’t-S            ill          tine       standing,                sitting,            bending,                and           squatting                      positions             is’as      noted,                 and          ap-
l)ropriate             photographs                          wer(         taken.
            Next,        i)y       111(11115           of      roentgenograrnS,                                   attempts               were          made         to determine                            the exact                 effect          of the braces                          on
51)iflaI       movement                     aii(i           position.                   These              tests        were            restricted              because                of the              risk          of overexposure                         to        roentgen

      BACK                         VIEW                                     FRONT                                      VIEW                                 BACK                             VIEW                                  FRONT                              VIEW
                                                              FIG.          1                                                                                                                                 FIG.         2
                                                                                                                                                        Fig.        1 : Drawing                        of the               long       Taylor              back              brace           on
                                                                                                                                                  the skeleton.    This is an example                                                      of a long                  brace               wnth
                                                                                                                                                  paraspinal    uprights which extend                                                       downward                         from           the
                                                                                                                                                  level        of the            scapular                  spines              to the pelvic      barid,     located
                                                                                                                                                  halfway                between                 the          iliac         crests   and     the     greater       tro-
                                                                                                                                                  (hanters.               Each               upright           is        inclined     toward        the mid-line
                                                                                                                                                 so     that        the         distance                   between              them    decreases         from     two
                                                                                                                                                  inches           at the pelvic                        band             to one inch in the interscap-
                                                                                                                                                 ular        region.             There               are       two         crossbars      in addition          to the
                                                                                                                                                  l)elvic          i)and,             one on the level of the eighth                                                   and            ninth
                                                                                                                                                 thoracic               vertei)rae,     the    other                                  six inches       below       this.
                                                                                                                                                 Straps              pass      forward    from     the                                 tips   of each      crossbar.
                                                                                                                                                  Those            from      the pelvic band and                                       middle    crossbar      attach
                                                                                                                                                  to a small                     abdominal                         pad           measuring              six           by          five       by
                                                                                                                                                 four        inches             : those          from              the upper               crossbar               encircle                  the
                                                                                                                                                  corresponding                            shoulder                and           buckle          to     the           tips           of     the

                                                                                                                                                      Fig.          2:         Sketch            of the                Arnold-Abbott                            brace              on the
                                                                                                                                                  skeleton.                   There           are two                  paraspinal                 uprights                   to     which

      BA C K V I E W                                                                    R            NT                v
                                                                                                                      ‘ I I             vv
                                                                                                                                        tAI       the
                                                                                                                                                  are       pelvnc baird, three
                                                                                                                                                             attached         lies crossbars.
                                                                                                                                                                                   midway                                              The
                                                                                                                                                                                                                                    between lowest iliac these,
                                                                                                                                                                                                                                                the      of crests
                                                                1’ 1G.
                                                                                                                                                  and greater
                                                                                                                                                  flexible and                       is trochanters.
                                                                                                                                                                                          molded                   and
                                                                                                                                                                                                                                 shaped middle followcrossl)ar iliacis
                                                                                                                                                                                                                                           to              the
                                                                                                                                                  (rests.           The              upper            band             is at        the       level        of      the            inferior
 aught’s            scal)ulae
                  of the           arid curves    forward        arid upward                                                                           beneath                 the         axillac            to      corresponding                     points                beneath
 the (‘lavicles    where      tine free ends   are joined        by a strap.                                                                      The          abdominal                     pad           is secured               by straps                extending                     for-
 ward    from   the ti1)s of tine two lower           crossbars.

      Fig.          3: Sketch               of a cinair-i)a(’k                                 i)race         on       the      skeleton.               This          is a short                     i)race           with         four        uprights,                two           para-
 sJ)inial         :ninnl two            mid-lateral,                  crosspieces.
                                                                        arid              The
                                                                                           thrree lowest         crossbar       or pelvic        h)an(1 is at the level                 of the
 sacrococcygeal                        junction                  but- curves
                                                                 l)ostriorl’          upward       and       forward        to lie midway             between          the iliac         crests
 aII(1 til(’ greatnr           tro(’hianters         in t he iuid-lateral          line : the nlid(lle          crossbar       extenrds      forward       along       the iliac (rests;
 tire     uper        0iii    is situ:Lt(d         at thu level         of the inferior         arngl(s         of the scapulae.             Each      crossl)ar         is (‘urved         arid
 shaped          to :ivoinl      h)OIIV l)roniin(nn(’(’s.         ‘Thhi( uper         and lower        011(5      are secure(l          to the 18t1ral          uJ)righnts        vhile       the
 flii(I(ll(’     Oii(    is free      tnt both (xtrennltn(’s ainti isiedial to the lateral uprights                                 so that it-may           fit-  smugly above the
 iliac (rests.
      ‘l’his l)ra(’(’ is secured                to the h)o(1\’ in’ four panrs             of straps,         a chest      strap      secured       to the upper            (rossi)ar        and
 three       i)airs     of stral)s          which     extend     from      the ends        of the crosspieces                to the abdominal               pad      which        measures
 a1)1)roxinr:nttlY            SiX h’ five          by four    iirches.
                                                                                                                                                                          THE              JOURNAL                    OF       BONE        AND         JOINT                 SURGERY
                                                                                              IMMOBILIZING                                           EFFICIENCY                                        OF          BACK                 BRACES                                                                                            113

ra(hiation.                         Hence                   only              lateral               views  of the subjects                                               standing                        and bending                            were made.                           A standard                            technique
was         adopte(i:                          a film fourteen                                      by seventeen   inches                                               was           used              with             the       cassette                    mounted                   in        a vertical                    holder.
This          molder                   (‘OUl(l                h)e rotated    in such a way as to permit
                                                                                                  on           adjustmeint
                                                                                                             a horizolrtal                          axis                                                                                                                                      of the                 plate          to     tine
(Iesire(l               angle : at the same      tinie it could be raised or lowered        so that the cassette       and                                                                                                                                                               the          x-ray             tube             were
always                  a(Ijliste(I at the level      of tire iliac (‘rests. The (listaflee   from  the roentgen       tube                                                                                                                                                                 to       the         cassette
tiiainltailie(l                       at            fotrr         and           one-half                     feet.;         the         subjects                    stood               n.s close                  to the               cassette                    as possible.                    The          slight-            errors
(lire       to      parallax                             were            therefore                      the          same              for     each                subject                    and            the         effects           of the                   various              braces                 on      the         spinal
nilOt 1011 of                       :n given                  sUh)je(’t               %‘((          comparable.              difficinity   was encountered
                                                                                                                                               Some            in obtaining     roerrtgenograms        of
sufiicielnt       clarity   to visualize                                                        tine outline     of tine sacrum.        A L’s’sholm grid was used in all instances.
            Tine nrovemerrt     i)etWeenr                                                       adjacent     vertel)rae   in tine lirmbar       region was measured      in the folloving      manner.
Eon’ eacin                    v(’rtebra                          a line             was         drawln                 through                     the          tips          of the              two           most             anterior                  projections                        of     the         anterior                 sur-
face        t)f         the           centrum.                           The          angles                  formed                   by      the              intersections                             of the                lines       drawn                     on      adjacent                    vertebrae                      were
measured                        arid                an’           changes                    in         these           angles                 [formed                       by        the            intersection                        of these                    linesj           were              recorded                   as     the
annoinints                    of        motion                      occurring                           at     the          intervening                            interspaces.                               For         the           sacrum                  the          line       corresponding                                to        its
anterior                   surface                        was            derived                    by        selecting                      two           points                 through                      which               to      draw                 the          line.         One            of     these              points
(orreslx)nr(led                                to the               most.             anterior                  prominence                               of the               first         sacral              vertebra;                  the            other            was         the         bony              prominen(’e
(orrespon(Iinng                                    to       the          junrction                   of the                first        and second                              sacral                 vertebrae                   or      of        the second                       arid          third,             depending
011       which                1)Oilit                   WaS           best          visualized                        on        all         of the               roentgenograms                                         of a particular                              subject.
            Measurements                                           of spinal                        movement                        by means                            of roentgenograms                                          are notoriously     inaccurate.      In to-:urd-
fro       niovenieiit                          ,    that           is,     from              complete                      extension                       to complete                                flexion,             Tanz       found    “ by repeating      the roent-genro-
grams              an(I              measurements                                     of several                      sini)jects               “     that               “tire           results                of these                 repeated                     ol)servat-ions                        usually                 agreed
ivit-hini               two            degrees”.                           Due              consi(leration                              must                be          given               to         the         existence                    of        such             errors             in      interpreting                         the
roerntgenographic                                             measurements.
            Furthermore,                                         since           there              is much                  individual                          variation                       in the              amount                 of motion                         in     the           lumbosacral                       spine
of normal                           subjects,                       as shown                         by Tanz                      arid         others,                   roentgenographic                                         studies                 were             obviously                     of very                limited
vltliie           for         the              l)resenit                  study.               The             effect             of a group                            of supports                           could              only         be          compared                     on          the         same            subject..
However,                            to test                  ten          braces               on the same                              subject                    would                 have                resulted                 in far too                      much             roentgen                      exposure.
       To oi)viate      this,   Kirschner-wire           markers    were     inserted       into    the    spinous     processes                                                                                                                                                              of      the            appropriate
lumbar      vertei)rae    arid into one of the posterior           surperior      spines     of the ilium,       an adaptation                                                                                                                                                               of the             method                   used
i)\’ Inmain      and his colleagues        inn their stint1’ of the shoulder          joint    . The    change     in the angles                                                                                                                                                             formed                  by adjacent
wires            offered                      a reasonai)lv                             ac(’urate                     method                   of recording                              the             motion                 occurring                      at the              intervening                         intersl)ace.
This          technique                              I)ermitte(I                        repeated                      deterniinationns,                                  1)0th            with               and          without                sirpports.
            The               sirbject                      stOo(i             before                a grid                screen              (Figs.                  4-A        and             4-B)             upon               which               there            were            lines           indicating                     sue-
(((5\(                  alngles                     of        15 (Iegre(’s                          from             the         vertical                   in         the        direction                         of         forward                Iwnd.                Photographs                               and        motion
pi(’tures                  wer(      lnSt(l to record    tint movement-s                                                                       of the                  sul)ject               arid the projecting       wires.    The center                                                                   of the camera
lens was                   a(IjilSte(1      to tine same     level as that                                                                     of the                  (entral                ss’ire when   the subject        was standing.                                                                    The   (Iist-an(e
from             tire         (‘amera                       hems to tire                      subject                  ‘as  twelve   feet.                                    Since              the          wires             were          moving                    in a plane                       at. 90         degrees                 to
tint       focal              axis             of the               lens,            an(1           since             the angles   being                                     recorded                     i’ere           those           descril)e(1                      by the                wires           one         with          an-
ot her,            (11015                  (line            to      l):tr:Lhhax                %s(r(            niinniiiial.
            Wii(in                   tine Sti1)ject                           ivas         sitting,              tire        camera                  was               readjusted                        to keel)                the loris on a level                                  with              that         of tint mi(1-
(Ile      wir(’,
            TIne              angles                      between                   tire       wires             were              (hetermined                            by projecting                                  the photographs                                   or the motionn                             pictures                 on
in ground-glass                                      s’n’een               ain(1           niarkinig                  tivo         points                  on          a sheet                   of      tracing                 pntr                on        the         image              of each                  wire.             Each
pair        of l)Oinits                            iias          subsequently                                (t)Iinn(’(tU(l                  i)\’ a straight                            line,            anti        the angles                       formed                  between                    these             lines         were
measured                        111’ iiieaiis                       of a I)rot.rlnctor                                and          l)arallel                    rule.
            Inn ad(hition,                                 tire         angle              fornied               i)etWeein      the wire in the pelvis arid onne of the irorizontal                                                                                                              litres on the s(’reen
ivas        determined.                                    This            servNl                 as a rough                 measunre of 1)elvic rotation.   The angles measured                                                                                                              between                   the         pelvic
wire          and             tine horizontal                                   at various                           degrees    of forward  bending     were directly proportional                                                                                                            to but             not          equral            to
tine       anrglcs                  of hip                  flexion                 associated                        wit-in           each          of          the          positions                      investigated.                           Since              there           is considerable                              back-
warti             shift-              of           tine          pelvis              (hlriing                 forward                   flexiorn                 with             the            knees              straight                  (the             backward                       shift            being            a corn-
PeinStLtOr’                    movement                                 Itinfle(l                 nit nnainrtniininng                               the center                      of gravity                             over           tine        feet),             the lower     extremities         are
inclined                   i)a(’kward                             fronii the                   vertical.        Hence                              the angle                      of hip flexion                                was        greater                   than    that  recorded        bet-weeni
tine       pelvic                   wire             and           the          horizontal                           in all         positions                      of forward                            bending.
            Inn order                          to         nnieasure                  tint           arnouint                 of motion                          of the                spine              and         pelvis,              a base                line          was          select-etl                arid       motion
ret’orde(I                    Its       (legrees                    of        flexion                or extension                             from               tins           level.                Accordingly’,                       the         angles                 formetl               by       adjacent                     wires
wit-in           each               other                  110(1 by                  tine         jslvic              wire             with              tire          irorizonntal                      in        the         standing                   position                 ni’ithout              aJ)paratnls                    %(I

used         as zero for                                  (a(hi           int.(’rsh)ac(’                     :tinl         for      J)(hVic               rotationi.                     It       i:ts         turns            possible                  to        r((v)i’(l         the  cinanges    l)ro(hlnc((l
I F’s     t he Various                                    siil)l)oi’(           5       Iii ( hI(              stLnI(hillg                    post         i1i’(         aind           (hinting                   h)en(hirng,              sit t ing,                  and          squat    t lug in t ei’rns of
flexion                 or (‘xi               (‘tiSIOil             fronnn            t his          zero            him.
            Tlneii’                   i(i’(               5(’v(’i’al             (hisa(lvaimt                   :nges            inimez’ennt-                   in this               te(inniqu(,                         inn a(1(hit           ion            to      the          (nm(N)imnt (r((h
                                                                                                                                                                                                                                                                                   (Iiff](ult            ics
in finding                          siil)jectS                    anm(h getting                          wires             PrOPerl3’                 innserted.                       For         inst-ante,                     the suni)jects                        grew           fatigined
                                                                                                                                                                                                                                                                                  anti tine local
anaesthesia                            t-ennd((1                  to       wear              off.        Altinough                      the wires                       were            riot (leforn0(1                            visih)hy                by t-(nmsionn of tine soft tisstn(’s,     it

VOl..         39-A,                 NO.            1, JANUARY                               ((57
114                                                                                                     P.       L.      NORTON                   AND            THORNTON                           BROWN

was          l)Ossih)l(                   t hunt           this          tennsioii                 altered             spinal          motionn.             Finally,             many             of the          braces              had         to      be         nnno(lified             in order
to      1)r(’v(’nnt                thin’ uprights                           or       (‘rossl)ars                  from           impinging                  on     the         wires.         These             modifications                          connsiste(l               in     offsetting
shmort          segments                          of        OIiP           of       tine           irprights              or crossbars.                     They          did         rnot change                   the        contour                  or rigidity                    of      the           up-

l)aratiis,               l)uit            of     course                  they       (101 alter  the                           location    of pressure      from      tine                             apparatus                for          the       parti(nilar                     area          of the
l)a(’k         ilnvOlVe(l.                        It        was           tIifTi(’lilt   to assess                             the influence      of these      factors                                 on the             results                obtainme(1.
             Inn nio(Iifyinmg                               time plastnr-of-Paris                                       jackets,             appropriately                      l)Iaced           slots         were       cut         inn the           l)lust(’r            to an’n’onnnio-
nlatn         tIne           projecting                           wires,             By            splitting              the         jacket         inn the        sagittal                plane           instead            of inn the                 conrvetmtionnal                        front-al

l)lLine,             t lie        tl)l)li(’itt 1011 aunt l(’Ii0)Vinl of the jacket                                                                  iere      facilitated.
              For            t lie rn)ennt germ st in(hins n f spitial     nnovennennt                                                                  roenntgenograniis                         inn t he         hat eI’al          prOje(’t            ion         \et’e           minnie            it         ii

                                                                            hn(;. 4-.\                                                                                                                                     Fto.        4-B
             Figs.                  .,4             LI1(I 4-13 : Siihjnn’t          standilng                                           and         berndirng       before                   grid         screen.       1irscinner-wire                          nrarkers     are
         inserte(1                   iii         tine 51)1110(15     t)rn)n’(’ss(’s        of                                   the      second,             third,    annd                  fourth             lunlhar     vertei)rae                      annd inn tine left
         pstn’rir      sul)erior  sn)inm(’ (if time ilium,  Note                                                                             the excursion                     of the wires      occurring                            ivith             30 degrees     of trunk
         h(en(1.  (I)ue to te(’iini(’al       error flO nrarker                                                                              was   placetl               iii     spirrous   pr((’ss        of                      tine fifth                  lumbar                 vertebra
         %Vimi(’hm ivas sninall                     to
                                 annnl (hifhi(’Ult locate.)

 t im(’ (III)j((’ts                        standing                        in       varinois                 niegren’s           of     forwarti             bending                  as    (leterniin(’d                 h’      a phinnib                 linne        unit!         1)rotra(tor.
  For         tire       wire              Stln(hieS,                    a similar                   technmique                 was          enl)loyed             ‘hen            still       pinotogral)irs                   were          beinng             made,            The             nnioving
 l)in’tlmr(’s                                     takenm,   however,      witin   time sul)ject                                                      making                 a series              of forward       bends,    The                                      angles             were  then
 znreusun’e(l                      i)\          SeIe(’t ing t inc frainin’ %Vlii(’in shiOWe(l                                                     the subject                inn the             proper    (legree    of forward                                       bennnh.          It was our
 iinnl)ressionn                      t hunt the                     subject                 ‘s 5l)iimt            was         nmot- nmecessarilv                   inel(l       inn the         same            position              every             time           that           lie iennt              to         a
 givn’n           l)oSitioIm,                     l)Iit           t his         hn:ns imot hecin                       in1V(stigltte(l.                Repeated                  deterniurnationns                      of tire         angles                 at- the           1over             iunrii)ar
 irmt erSI)itcUs                          1)        t lie           h.irschnn(’r-wire                                 techniniqire             revealed             tinat        , inn       t inc      same           Positions                  arid          wit      in t in(            5iiiii(’          nip-
  paratirs,                   thmer(’               \%(5            :t     wide              sl)rend              inn the             values           recorded.                 The          results            niurst         therefore                      l)e     intnrh)I’(’te(l                       witin
                In      or(hn’r                 t 0 (let (rliiilie                         t lit      forces            Produi’nd               bet veen            t he        back          anal      t lie     sii1)pOn’ts               at- various                  levels,              iressui’e-
  r((’n)rnhing                     (ln’vices                 were               nlevelopnd                      with          tIne     assistance                of the            I )epurtniernt                  of Civil             Ennginneering                         :nt the                \Iass:L-
 (‘hmLis(’t ts Inst                         itute      of Techmnmology .                                       Sinnple           hydraulic               gauges             with           attached              pressuirt’             shoes             to make                conit.an’t                  wit In
  t Inc i)aA’k                 vere               tried first , but t lose                                        1)rove(1             unsatisfactory.                         Tine        pressure             simoes         were          too large,                   aunt          tine        gairges
  n’re           riot-             Siifl1(’ iernt Iv                      seimsit           ivn.         Subsequent                    ly,      sinialler          annd          niuncin        niore            sat-isfa(’t-ory                   (levi(’(’s             ‘nre              (levelope(l
  %Vimi(’ii           (nmnl)loVed                          ele(’t         n’in’al st rain                      gauges           anmd a recorder,
               I’an’hi             )ressun’e-rec’ordinng                                           deVice             (Fig.          5) was         (‘omposed                  of a cnuntilever                   beann          (‘laniped                at its          fixed             (‘11(1 to          tine

  ort.ionns                   of         tine      brace                 winier             investigation                        by      means            of a mournting                        block.           Attachetl                  to the free end                            of tine lever

                                                                                                                                                                                            THE         JOURNAL                 ((F     BONEAND                          JOINT                SURGERY
                                                                                  IMMOBILIZING                                            EFFICIENCY                             OF         BACK               BRACES                                                                                       115

i’as        a Pressllrt’                      foot          \Viii(’il           could              be           adjinsted                  forwarti                 or       i)ackward                   in     order           to         i)rinng          it inn contact-                     with            the
iSL(’k.           Aiiy           force             applieti               to          the         pressure                      shoe            would              then          produce                  a bendirng                       strairn            inn tine         caintilever.                      By
Iii(’tilS          of          two          strain            gauges                        (‘(‘nienntc(l                   to       the         cantilever and connnected                                               to         a Sanborn                       Z’(’cOrder,               :tniy       force
 L1)I)hie(l             to      tIne pressure                           shoe          could              be recorded                            in the form of a curve.
            With               this         apparatus                     it was              possible                     to record                   the         forces         developed                     sinninit-aineously                            at     five      different                 levels
011      the       uprights                   or      crossbars                       of a brace.
            In additioni,                          devices               employing                        the         same                principles                 were         made             to record                  the         force            exerted            by        the     shoulder
straps,             abdominal                        pa(ls,             and           the         like          winere              they          ma(le             contact.            with             the     body.                  These              devices           proved                  unsatis-
f:uctorv                since          they           torrid             not          be adapted                           to      the         wi(lelv             different                contours              of these                   Parts            of the          i)ody.            In       retro-
51)(nt,    it. would  have   i)eenn                                         preferable                          to        record               tension             inn the           straps          rather              than              the        force          betweenm                 tine      straps
:nnmnl  tine I)O(i\’sirrface,
            The              recording                 tlevi(’es                which               were              clampetl                   to the             irprights                1)roved            reasonably                         adeqinate.                 However,                     witin

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                                                                                                                                                                                                                                           SET              SCgEW
                        MOUNTiNG                            LOCI<
                                                                                                                                                                                                                                           3LOiI<              HOLDING-
                                                                                                                                                                                                                                                 ET          SCREW

                        .crgAIN                      G?k4CS.__                                                                                                                                                                            AL
                             cr1eNrfo                         Tb          c?1w17L.E                                                                                                                                       . -       -                                       CONTROL

                        TWo            BOn.TS                                     ,                                                                                                                                                               ROTATIOt4OFKOE
                          (i     foiT’iN6.                      15I4

                    AALE                     ipi      C4piTi-                     --:-                     -‘         -    - - -

                             I/e*                      BEn.i.j

                    3LocIa                     #{248}J ND
                                                     E                     OA.                                                                                                                                                  -         SKIN                SunAci
                               AXLE                TNDL4-N
                                wtf1,It                     Bo&7c                 lc,qoftl
                                             ME                Tl1f,qOtD
                                                                                                                                                           Fink.         5
                         Pressurc-recordinig              device      niounnted         on the brace             u)right.         The prinicipal elements                of tins
                    (levine      are tine cantilever            beam        clanipetl      to the upright             at one       end,   the pressure        foot,    arid the
                    strain       gauges.        The    pressure        foot      is adjusted        against        the skinn surface             by turning         the bolts.
                    Anm’ inncrease           in pressure         between          the subject’s        body       and     the pressure         shoe    produces        a back-
                    ward deflet’tionr             of the cantilever.              This   deflection         causes      a change        in tennsion      of the electrical
                    strain      gauges       cemented         on the cantilever.             By appropriate              electrical      connection        to the Sanbornm
                    Recorder          tinis change        inn tension        is recorded         as a curve         from      which     the POUndS         of force       onn tine
                    pressure        shoe      could    be deterniunned.

tineir           attached                    electrical                   cah)les,                they               increased                    the        weight              of      the        apparatus                           considerably.                        Furthermore,         it
proved                  impossible                    to adjurst                      the         pressure                      shoes           so as to reproduce                                 the         contour                   of the brace                       exactly.     Finally,
tinese           I’e(’ordinng                 tievices                  were          of such                   a size             that         the        pressure               shoes           could           not.        be          placed             at     exactly              comparai)le
levels            inn all            inistances                 dine        to        tine        presence                      of crossbars                       and         the      like.
               Inn order                to     determine                         the         force              exerted                   by      the        plaster-of-Paris                            jackets,               holes             were             cut      inn the           plaster             inn
tIne appropriate                               places,              arnti        the          recording                         devices               were          mounted                  on     duraluminum                                strips             bolted           to the             outside
of the             jacket.                By         this          method                   the          pressure                   feet         could             be        adjusted               to        fit into              the      holes            anm(i record                    the       forces
(levelopeti                     at     these           points.
            It- ‘as                  nnot possible                        with              these               irnstrument-s                         to     measure                  the         forces          (ieveloped                          by      (‘OrsetS             or     similar               iLl)
            *     8R4                 A-8          strain               gauges               were               used.              These              are          fine,        hair-like                wires           whose                   electrical                 resistarnce                 varies
  hirectly           the tensionn
                         with      applied       to them.      When     appropriately          secured  to the cantilever       and connected          to the
recorder     as a Whe.atstorne       i)rndge    in balance,      changes       in their    resistance    caused      by the bending    stresses       on the
canntilever    disturb     the halannce      in the bridge        and produce          a flow of current        and a corresponding        deflection       of
the stylus of the recorder.             The gauges        were    compensated           for temperature         arid sealed   in wax   to obviate         the
(‘ff(’t’ts of moisture.

VOL.            39-A,          NO,        1, JANUARY                           1957
1 16                                                                                           i.         L.       NORTON                     AND              THORNTON                           BROWN

             Inmevitah)lv                      the           l)r(’5(’ni(’(              of      rn’(’on’ding                   nlevices                 on     the         sul)1)orts             channged                   their           behavior              to     some              extent.
lii(’        te(inniques                       elnnplOVn’(h                    i(’li            oh )viously                     (‘I’lm(le         ILii(1       t he      (lisI’r(’t)aln(’i(s                  iii         sonie         of      the         n’esult s n’oinld                 be      at-
t rii)lit      (‘(1 to            these              t n’n’hnnin’al            (l(fe(’ts,
             I’orwar(l                  I)eln(lumg               as ()r( linian’ily                         re(’n)n’ded               in chni(’al                 pr:L(’t-i(’e           r(’l)I’esenmt              s a     connrpoutn(i                nniovennient                  involving
flexionm            nnf    i)Ot     ii t-Ii(’ iiih)s                anti          of      ( lie       sl)iii(’.           hIm t hmese eXl)eriniielits,                              tint        aniount               of forward                     henmditmg was                   estiiniated
as t Inc anmgle                    fornied                   I ret-weeim               t Inn’ vent             in’al      anntl an            inniagirnary                  lime        thnawii         fronr             t ire sacrunni               to t lne t iroracolirnnii)ar
jrnnmctiorn.               This            refereince                     poiint              prove(l                  more           satisfactory                     tharn            using          onne         higher             orn the             spinre,       for there                  was
wide          variation                    inn dorsal                   flexibility.                      Arm occasiormal                         subject              could            approach                    the      horizontal                 or 90 tlegrees                      of flex-
ion         wit-h         his       shoulders                     bunt         tine           lumbar               region               did       not         attain           more             than        50 to             60       degrees              of forwartl                betiding.
             Inn order                  tt) obtaini                a graphic                        record              of forward                      bendinng             to     i)e correlated                         with         determinnations                         of force,              an
aumtoniati(’                    goniornet-er                      %!.(5        develn)pe(1                        (Figs.           6-A        an(1           6-B).         This          was       composed     of two 1)arts: a potentiometer
set’ure(I            to time thigh                           at- the           level            of tine hip joint.,                           anti            a rod projecting                         downward    in the axis of tine trunnnk rind
secure(l              rigidly               at         its       upper                 end          to      the          thorax.              The             rod was attached                           to the axle of the potentiometer        by
nieanns             of a sliding                      couplirng.                  \\ith              this         arrangement                           flexion            or extension                    of the             trinnk            or     hips       would              rotate           the
axle         of the             potenntionieter,                            channging                       its        resistance                 anti         thereby              caursing               a flow            of current                  anti        a corresponding
(lefle(’tiorn               of      tine        stylus             of      tine         Sannbornn                  recorder.                  The            resulting             curve           was         calibrated                     in     degrees            aind         a continu-
Otis        recortlinmg                 of i)Otln                                         anm(i bend                     (0111(1 thus                   be     made.              The       goniometer                       proved                reasonably              satisfactory,
hint        snnie          (lifficultv                     was       enr(’oulntered                            inn securing                   the        potentiometer                           rigidly             to tire           thigh.          The        size         anid      contour
of     the      thigh              chainges                   as the            result               of variationns                        in the             tone         of the          thigh           musculature.                            Inevitably              some             change
in     the      relationship                           of the             potentiometer                                 and         the       thigh            resulted,                introducing                       air error            of ap)roxirnately                            plirs       or
nhiniins            5 degrees                   inn the            nieasirremennts                                of bennding.


               Observation                                     of the                  action                     of the              various                   types    of supports      with the                                                     subjects   in differ-
enit          positions                          iridicates                            that              apparatus                        which                   is well fixed      to the chest                                                      but inadequately
attached      to the pelvis                                                     tends   to produce                                            a concentration                                       of force                   in the upper  lumbar                                                and
thoracolumbar        regions                                                     as the trunk     goes                                            into            fiexion.                 The        lower                   end of the apparatus                                                 lifts
away     from                           the            sacral                region                       (Fig.              7),       limiting                      motion                of the                   upper               levels              and          leaving                    the
lumbosacral                                   segments                            unsupported.                                        This               behavior                        was           noted                  with              the           Taylor                  and           the
Arnold-Abbott                                          braces,                     and               with               plaster                jackets.
               In         contrast                         to these                     are           the          short                supports,                      such              as the             Goldthwait                               and        the        chair-back
i)races               arld               corsets.                       These                   have                   little              if any               fixation                   to       the             chest              but            are       relatively                      well
secured                    to the                     pelvis.                  With                  these                the          tendency                        for         the          lower                end           of the              apparatus                        to pull
away                from      the                      body  is much    less                                              (Fig. 8). Quite   obviously                                                      relatively                          little  force                   is exerted
inn this              instance                          but w’hat pressure                                                 is developed   is maintained                                                         at the                       lumbosacral                        junction.
       Rather      to our’ surprise,      but in accordance              with     the previously          observed     behavior       of
back    supports,      roentgeniographic         studies      of spinal      motion       revealed     that    some braces      actu-
ally increased        lumbosacral        motion,      when      motion       with    the brace       was compared          with    the
motion      measured        in control     bending       without       support       (Fig.     9). This     effect  seemed      to be
related                   to the concentration                                                            of force                    in      the            thoracolumbar                                    region                   produced                   by           the       longer
i)races.                   By limiting      spinal                                                   fiexion                    111        this              regiorl,              compensatory                                        movement                          presumably
occurred                          below                .      This              effect                    became                       manifest                     usually     in the higher    degrees  of forward
bending,                         i)ut          iii         some             instances                             it was                apparerlt                     at 30 degrees   (Figs.  23 and 24). It did not
occur                with                all          long              braces                      nor           with              every                    subject,       but the fact that    a brace improperly
selected                    or fitted                          might         he deleterious                                                had not occurred                                        to us. Needless to say, this                                                               effect
may not                      be present                                 in patients     having                                             back symptoms.                                         This has not been investigated.
              Although                               it i’as              appreciated                                    that           the             range            of motion                      in the                    lower              lumbar               interspaces
varies                considerably,                                       as           emphasized                                  by         Tanz,                  the          present                  study                   suggests                   further                  that            in
normal                     forward                           bending                          f-here                   are         other                 variations.                            These                 include                      such           things                 as         the
amouunt     of hip motion     arid the                                                                            pOirlt              in      the            arc of forward                                 bending                      of the                trunk             at         which
the fiexion    possible   at a given                                                                           interspace                          is        expended.
              The                site          iii the                  body                  where                 the            greatest                    flexion                  occurs             during                      forward                  bendirlg                  varies
greatly  with the individual.      At one extreme        there     is the person      who bends      forward                                                                                                                                                                            prima-
rily by hip fiexion   (Fig.   10), while    at the other        there    is the so-called     “ham-strung”                                                                                                                                                                                  mdi-
vidual  who appears     to bend     forward    primarily       by spinal      flexion   (Fig.  1 1). Between                                                                                                                                                                              these

                                                                                                                                                                                        THE        JOURNAL                        OF    BONE            AND          JOINT            SURGERY
                                                                                        IMMOBILIZING                              EFFICIENCY                              OF          BACK             BRACES                                                                                   117

                                                                                                                                                                                                             1”iG, 6-13

                                                                                                                                                          I”ig. 6-A : Side       View       of a subje(’t     ivn’arnng   ‘l’avlor
                                                                                                                                                     h)ack     brace     iit hi re(’or(iing      devin’es    n’lanpn’n I I 0 the
                                                                                                                                                     uprights.       NOt(’   t he gonnionieter        On t inn l)11t(’ st r:npx’d
                                                                    ,                                                                                t n) t inc               left       t high.     tine            vertical           ro(l         se(’ur(’n      I        to         t inc
                                                               I, in;.          (‘-\.                                                                thorax,                  runni      tIne sliding                cou)hmng             on         tine        axle        of         th(’
                                                                                                                                                  gn)imiOnleter                           ivinich             1x’rnnit       s      I )n)t in inoriz(                 )Il t :n I     a innI
         vnrt nn’:n nlnOV(’llin’nnt
                                  S                                     n   )f t inn’ vn’r( in’:tl ron I ivitim                         ref(’r(Imce      to tine                       gonnionieter.
             l’ig. 6-13 : Sui )jen’t     I )n’nnnhinng In ri:nrnl  ivhnile ivearinig         I )ra(’e runnl recortiiing                                                                                          nlevices.    Note     thin’ rel:nt noishnil)
         n)f (Inn trssure         shuns       to  tinn i)flA’k. \I:nxiiniuiini    iin(l(’Inta.tiOnl      of the skin                                                                                           is at tinoran’olirnnnhar            jinin(’tin)n,
         ivhniln t Inn’ r’ssumrt’      shno’s      it tn)l) anm(l hot totni 01 ( lie h)ran’e ar(’ tmn)t (‘VUII                                                                                                 iii connt:nn’t    %Vi( In t hi(’ skin . ‘FIne
         act innnn))I tinn slinhinng (‘nnr)linng on gn)nnionm(’tn’r n’:nnnbe sn’eni.

ext n’ennies                    are            all        niannnnen’                      of      \‘an’iat         lonis.              Since               oirly              a few               subjects               ila\’e          heenr              studied,                        it     is
trot         pn)ssii)le                     (‘itiiCt            to            (‘lassily              these            ‘ariationns                          (Jr to             tt5S(5S             s’hat,            if anything,                       is their                    signnifi-
n’tIin’(’.             )nlatn’                 of I ireni                      are         difficult               to           expiaitn                 ttnitl          may             even          represent-                   experinlenital                                 errors.
I I n)\V(V(t’,                   l)e(’uliat’                    j)henronlenna,                               su(’h             as extetrsioii                            of      the         fifth         lumbar                 interspace                          durinrg                   t iie
first          1 .5 (Iegi’ees                           of          fon’ward                      i)enn(linng,                   were             inoted                 on           more           than            one           occasionn.                     One               rather
arrest           inig          finndinng                      vas             that             a nrurlll)er                 of sunbje(ts                           seemed                    to      expend                tile       frill      range                   of fiexioni
fl\’Lihui)le                    inn tine                  lurlli)n)sa(’nal                             joinrt             (turning                tile          first.          30 (legrees     of forvard      benndinrg                                                           of       the
trunk.                 ‘FIns            suggests                              that          ani       effecti’e                       support                   for           the immol)ilizafioni        of tins joinmt                                                           should
CXer’t           its          (‘fit1(t               (linrinrg                  tile        first        30        degrees                        of trunk                     bend.
              ( )f interest                            also                 is the          amount                    of lumi)ar                          fiexion                    oi)served                during               sitting,                 as        pre’iouisly
Oi)sel(’e(l                     i)\’          Keeganr.                          \Vhenr               this          s’as               compared                           w’ith           the         lumi)ar                flexioni             associate(1                             vith
nlaxinurnl                        forward                               betiding                     (Fig.           12),              it      ‘as           apparent                           from           the         few         inicomj)lete                              stu(iies

nla(le               1.-lint          even               inn tine                    erect-          sittinng               positiorl                     a substanrtial                             amount                  of      fiexion                 occurred.                            Inn
the          slunllxnJ                         i)sitionn,                          on          the       other                  ha-rid,              flexiOnl                    i)et\\’eenl               the        fornrth                 arid           fifth               lumbar
‘erteitt’tte                     a(’tl.tItllv                           eXceede(l                    tlntnt          0i)serve(l                          durinng                 maximum                           forward               bendinng,                          ‘hile                 at
the          r’ensainninng                        lunlbar                        inrterspaees                        it         ‘as           somewhat                            less         but         still      considerable.
               llnes#{128} oi)sel’vationns                                               enll)hasize                       tile             importance                               of sitting                as      a cause                  of stress                          on        the
lOW          i)I(t’k           arid            singgest                        thtt            a su)port                        for         the          lumbar                   arid          lumhosacral                         portions                     of       tile       spitne
511001(1               l)(’      eI1c(t                I\’(             inn tine           sittinng             j)()Sitioti                    as        vell            as       during               forvard                    bending.
              Alt lnoungln                       Ion’ r’easotis                            Pre\’iOtn5l’                         niennt-ionnecl                        our         studies              on the               effect.            of hack                     supports
on        tine         I)05t-uit’t’                    iunnti                nliovenlcnnt                     of          the          lumbar                     spine                have            i)eenl          rat-her                insconrelusive,                                tine
fin(hngs                  are           of’ interest                               arid          vort.iiy                 of          comment.

Vnnl..       39-A.        No.          I,     JANIARY                          1957
115   1’.   L.   NORTON   AND   THORNTON         BROWN





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                                           THE   J()UIINAL   OF   14ONE   AND   JOINT            SURGERY
                                                                          IMMOBILIZING                                 EFFICIENCY                         OF       BACK             BRACES                                                                        119

                                                                                            FORWARD                                                         BEND

                          450                      ANGLE                                                       :                                          FULL                                 BEND
                                                     BRACE                                  NO                  BRACE                                                                 BRACE                                   NO          BRACE
                                                             :                                                  #{149}                                                                         :J
                L4-L5                                 167.5#{176}                                      166.00                                  L4-L5                                          175#{176}                                  175#{176}

                L5-SI                                 139.5#{176}                                      136.5#{176}                             L5-SI                                          143#{176}                                  140#{176}


                                                                                  BRACED                                    SPINE                  “NOT                  BRACED”
                                                                                  AT            LOWER                            TWO                 INTERSPACES
                                                                                                                                   Fin.       9

                  ‘Fr:ucings        of lateral      rn)enntg(’nnogr:Lnss            of a subject           beinding       forward       to 45 tlegrees           an(I to t Inc Iniaxi-
            innuini ivearming            ann Arnnold-Abbott                brace      anr(i without           rinny a1)l)aratUs.         ‘l’he sacral        tracings         are suIx’r-
            Iiiil)()seni.      At. 45 (iegrens           of forwartl           bending         fin’xionn at the fourth              arid fifth lumbar              inntersl)aces        was
            slightly         nnore     ivlienn thin hran’n’ iv:ns worn,                 At full forward             i)(’nndinng flexionn       at the fifth interspa(’(’                was
            greater         when        tine l)ran’e      was worn            but at the inmtersl)ace                 al)OVe      there     was no differennce.                Altiroughi
            t his effect         (Ii(I tiot o(’(’ur       (‘n)nnsistenntlv        it :LPPt’ar(’d         to he due         to tine :11)1)rnratus        ivhicin      tnrmded       to cn)nn-
            n’ent rate        force      againist     t Inn’ t iioracolunih)ar             region       of tine back          as flexion      progresse(1.

                ‘FIse       effect             of supports                              on the                 positionn               assumed                    by        the        lumbar                  spinre            inn stansdinig                  i’as
recorded                    1’          conipar-inrg                      tue          position                    of the          spine           inn each               stni)ject-             ivith          a-nd          without              support.
\Vitii             i)1nt- few                 eX(’(’l)t.i()nis                   tile       apparatus                            tested            Caused                 flexionn               of     the           two         interspaces                     be-
tweerr               tue          fourth                  lunlbar                 arid          first              sticial          vertebrae                       afl(1         exteniSioll                   of       t lie      interspace                    be-
t.\Veetl            th(          third             arid          fourth                lumbar                  \‘entel)rae                  (Figs.             23,        24,       and          25).          TIle          factors            governunig
initersl)ace                      position                   were               riot       made                    (lear          by        the          tests,           altilOtngh                  it is’as               thought               that           ott-

detected                    localized                     pressure                from the uprights    might                                                have been responsii)le                                            for       tue     extennsionr
at        the       uiper                inlt-erspa(e.                        1ile teli(leney    of a support                                                 to produce  flexioni                                       of the           lunii)ar              seg-
niennts             (li(l        riot        seeni           1elittNl                   to ann’              l)art-i(’ular                  designi.              Sinrprisitigly                        enoungh,                 the      effect          of tine
slnl)l)Oi’t                On          adjacent-                  innterspaces                          inn tile             sanie            spine               i’as          t)(casiollally                        reversed,                 one          i)einig
eXt       (9i(led               arK!         the          ot lner          flexed,              on          ‘iceversa.
                I rrespective                        of tiiP               standing                     or start.inng                       posit-iotn,                  forvard                 benidinng                  was         a((0mpanii(t1
l)\’       interspace                         flexions,              (‘x(eI)t               at.         tile           tiiir(I         or      foui’th               lumbar                   interspace                       w’ilere          ext-etnsionn
soninetirines                     occurne(I.                      Inn general,                         at        the         two          lower            inlterspaces                       three            effects              i’ere        observed
(linrinig            forw’ar-d                     1)enn(litng            :     (I ) a         re(luctionn                       inn the          amount-                   of      mo’emennt,                         (2)        a change                in      tire
arc        of niovemennt                              to cit-hen                  tile      flexioni                   on    extension                    si(le          of neutral,                    arid          (3)        although               rarely,
ann iti(’i’eUse                    in total                 nlovemennt.                           Inn all              of the             subjects                 tested,              a strikinig                    lack            of consistency
in      tine        effect              of     tue various                             types            of apparatus                              i’as         evident,                 particularly                          at. the           two          lower
un      ensiaces.
                 Iliene                            sorlie           evi(Ienice                    to           suggest-             that            air        ade(Iuate                      abdonlitnal                     support                  may             i)e
t’esl)(         )n nsi I )le           for     nonisi(lenal)le                           inimobil                   izatiorn           ; for          example                     t he        \Villianis                    i)race,           ‘hicii            the-
oneti(allv                      SilOtlid              allow               free           flexionn,                 (ause(I              some              limitationi                    of      lumbar                     moveniennt-                 tlurinng
forivard                   i)endinng.

Vn)L.       39-A.         NO.      1, JANIJAI(Y                    1957
120                                                               P.    I.      NORTON                   AND      THORNTON                   BROWN

                                  FORL/ARDBEND NO SUPPORT                                                                         -

                                         ONE MODEL
                             B                                                                                                                                                                        ‘60’

                                                                       GROSS TRUNK BEND
                                                                                                           Fnr.     10

                            ‘%In)tionm of tim(’ ln)rv(r tinr(’e lunnnhar            innterspaces        ann(1 pelvic   rotatiorn        of sui)je(’t-   B tluriimg
                       f( )rwar(1     i)n’nnniinmg ( ii )n’isS.tt ) . Zero    (legrees      of intersl)ace        niot ionn or ix’lvic         rotat iorn (orthi-
                       mate ) (‘n)rresponn(ls        tn) t Inc Position         of each intersl)ace            ann(i of the      pelvis     (as inrtlicated       by
                       I Inn’ l’%.irschnn(’r-wire      rni:nrkers)     wli(’mi tire suI)je(’t      was starnding.        ‘Fine channges          in the relatiV(’
                       1)sitioim        of tine i’irns       nhuriimg forivar(l       bending       reflect   the nit)tionn   of tire vertei)rae        ann(l
                       pn’lvis,      flt’xionn     h)eilng  u1)war(l    111(1 extension         (iOi%’nnWard.      At each    initerSl)an’e    tine curve
                       iinnhin’atn’s      thin’ (‘ln:nngn’ iii tine angles      fornled       by a(ijacennt      wires.   For the pelvis,       tine curve
                       iin(hin’at(’s                     on
                                          cin:nrng(’s tIne :nnngln’     fornnied I’ the i)elvic ivire vitin relation to tine horizontal

            Inn     tire      sittinig        positionn                th(           (‘onrvetrt-iorlal                 supports              decreased                the          amount                    of     lrnnhi)ar
flexionr           assoniateol               ‘ith          both              tine        erect           an(l      the        slumpe(l             positions,               iHit           trot-ne        \VC1’(         corn-

l)l(t      eli’ cf1((’t,i \‘P             i ti I)t’(V(’tnt I nig flexionn                         (1”ig.        27).
             \leasltI’(nllennts                 n)f fon’n’e pn)(lIn(’((l                         against.              the    i)ack          by    the     van’ioins               ty)eS             t)f tti)I)ntn’nLt.lIs
\vet’e        nlruie         rut. se’en’at            point        s alonng               th(       I)ack         from         tine       level     of    tile        sixth           tllora(ic                   vertel)ra
t 0 t lie         san’n’n)n’n)(’(’ygeal               jtltn(’t.iOtn.                As     the      result.         of the            diflerenit         i’eight-s             of the                sul)I)Orts               Ittn(1
f-lie      iiivolittntrt’v                (‘haniges            inn     I)Ostrnre                 of the           subjects,              it proved               impossil)le                     to       trdjunst             the

                                                                                                                                      TilE     JOURNAL           OF     BONI          AND            JOINT         SURGERY
                                                                   IMMOBILIZING                            EFFICIENCY                       OF     BACK             BRACES                                                                     121

startinng                 forces          on         the         gauges                  at- strictly             comparable                       values               for      all of the                   supports                tested.
Furthermore,                            the      inevitable                       changes                in contour                    of the          supports                resulting                from            the       presence
of tine recor(iinng                           (levices                 were         \‘ariai)le.            Hence,                the      values            obtained                   could           i)e cOrlsidered                        only
roughly                   comparai)le                      to      those            actually               developed                     between                  the     back           arld          a giverl               support                inn
the   absenrce     of the gauges.     For’ the same          reasons,                                                                            the        forces             developed                      i)y      the        differenrt
types    of apl)aratuns   ver’e riot- strictly     cornparal)le.
       All of the lonng i)races     caused     pressure       inn the                                                                       lumbar                arid         lower         dorsal regionns,                            which
reaeile(l                 a. maximum                        as         full      forward                 berndinig               was       attained.                    Above            arid below     these                           levels,

as might                    he expected,                          the          pressure                 decreased                 during               fiexioni,              since          the       sacrum                 arid       upper

                                          EOkWAPD                                                      ELND-NO                                                           SUPPORT
                                                                                                       4 MODELS

                                                                                             GP.055                          TkUNK..                          BEND

                                                                                                                     FIG.         11
                Motionn             of tine       lower            three         lumbar           innterspaces              and         pelvic         rotation          of four         subjects              (see     legennd         for
            Fig.          10).     Note        the         variations                inn the           mariner    in which                   flexion    occurs at those interspaces       in tine
            rotatnon             of the        Pelvis.           For          subjects         P arid        L all available                    flexion at the fifth lumbar    interspace    nil)-
            l)n’:Lrs       to    have         been         34) degrees
                                                           expended                 at
                                                                           of forward      bending.     Subject   P who on clinical      exam-
            innnttiOli     ila(l tight hanustrinngs    and limited     forivard    bending     shows the most flexion of the third ann(1
            fifth      luinsi)ar   innterspaces.    The high degree       of pelvic rotation        exhibited   by this subject     seems      in-
            consistent             with         the    chinnical     evidence                      of tight          harnstrirngs.              No exjlanation                         for     this         apparent            inncotn-
            sistency             was       founnd.        Tire     measuremennts                          on         subjects              P and J were                         made           with           Kirschrner-wire
            iniarkers,           while         bending         roentgennogranns                         were          used      for        subjects     L and                  X.

(lOt’Stl             regions              nnoved                                  from          tile       l)race           as     i)en(iing               progressed.                       Some              variation                 inn the
                    wii    In which     pressure                             was    built-   nip i)y the                               various             braces              i’as          recorded                  hint     technical
(lifIi(ttlt            ies asso(iat-e(1         ‘it                       ii adjust      inig compan’al)le                                   starting               or’ st.andi                rig pressures                         ma(le           it.
(Iifli(’tilt             to initerl)ret      tli(5e                            difien’ennces               in tire           early           phases               of l)elrdinng                  ( Fig. 29).
              l’ire         maximum                      forces               recorded                 at 60 degrees                      of forward                     benndinng                 in the           lumbar              regionn
varied               considerably,                          ranging                  from              eighteen             to         fifty-six            pounds.                   With            the       short           supports,

VOL..       39-A,         NO.      1. JANUARY                   1957
122                                                            P.   L.     NORTON                 AND   THORNTON                       BROWN

                                      5UNC        vs. FORWARD                                                                                            bEND
                                        NIERSPACE         MOThON
                                                 4 MODELS

              Lunnni)ar            ulexion       of fourr sui)jects      inn the erect           and      slumped         sitting     positions           compared            withi their
          lumbar            flexion        occurrinng     with      full forward          bending.          Note     that       at the fourth             lumbar        interspace          in
          the three         subjects        tested       more      spinal         flexion      accompanied               the slumped              sitting       posture         than      oc-
          curred      inn full       forward         l)endinrg.       Even          in the       erect       sitting      position       considerable               lumbar          flexion
          occurred,        Inotai)lv      at the fifth          lumbar          interspace          in subject         P. The studies               on all of these subjects
          are   innconniplete        for tine followirng           reasons:          A!, no wire in the fifth lumbar                         spinous         process;         J, no wire
          inn the seconti          lumbar        spinous        process:          B, no wire in the second                        or third      lumbar spinous
          anm(1 the wire          in the ilium           hati i)een         dislodged          I)y the crossbar               of a brace         before        this    test     was per-
          formed      : P, lit) wire in the second                    or third          lumbar         spinous       processes.

such         as    t.iit’     Goldt.hw’ait                 brace         anid      chair-back             brace,            none          of the        recorded         values        exceeded
thirty-five                  pounds.            With          the        lonlger         supports,             such              as     the       Arnold-Abbott,                  Taylor,      arid
.Jewett            i)r’aCes,           and      plaster-of-Paris                       jackets,         the      pressures                    ranged     from       thirty         to   fifty-five
           ‘l’here           is some           inidicationn            that        the      amount            of force                developed          by most             of the     support-s
is    inrfluennced               by     tine       patterns         of lumbar               fiexion.          Tests   made                    on subject    B (Fig.                29) showed
that-       comparatively                          small      forces            were       developed             with most                     types   of supports.                Inn his case,
forvard              i)ending                was       accompanied                       by minnimal                  flexioll           of      the   lumbar         initerspaces              (Fig.

                                                                                                                            THE         JOURNAL         OF   BONE     AND       JOINT     SURGERY
                                                             IMMOBILIZING                          EFFICIENCY                    OF        BACK            BRACES                                                              123

                                                            DEVELOPMENT                            AND        TESTiNG                OF         NEW           BRACES

          As       the        study           of back                supports                progressed,                   it seemed                   worth           while          to     try         to develop                   a
mew brace    for lumbosacral        immobilization.                                                                  The        objective                     was      to design   a brace    which
ivould apply    sharply   localized    pressure                                                            at this         level during                       the     first few degrees    of trunk
bend        and           yet       be comfortable                           in the              standing               and         erect           sitting         positioni.
          Two brace    designs      were     tested. The      first,  called       the reinforced      Taylor     brace,      cons-
sisted   of a conventional         Taylor      brace made      of spring       steel,   the uprights    having     been made
rigid by duraluminum             reinforcements       extending        from the level of the third             lumbar      verte-
bra to the pelvic        band.
       The second,      referred      to as the experimental            brace,       was designed    to produce       localized
pressure              over          the       posterior                superior                  spines        of the           ilium            by      means           of a horizontal                         bar.         The
usual         paraspinal      uprights                             were to be eliminated          and replaced       with    mid-lateral       uprights.
rfhis       region      was selected                            as the pressure     point   for the horizontal       bar, because        force applied
here        was found       to build                           up rapidly.      In a simple    experiment      (Fig.    13), in which        a pressure-
recording                 device             was        advanced                     gradually                against               various             locations               on     the         back          of a sub-
ject lying     prone     on a hard     surface,       the force    developed       was measured.        By plotting                                                                                                           this
force  against      the displacement         it was apparent          (Fig.    14) that   the most     rapid  increase                                                                                                            of
force  occurred       at the posterior       superior     iliac spines      or just caudal    to them.
       Still              another              reason    for selecting     this pressure       point                                                      was that     in this    position                                    any
tendency                   of the           brace     to move     cephalad     during    forward                                                        bending    served      to increase                                     the
pressure    of the horizontal                                        bar      on the              projecting                  posterior                superior           iliac          spines            and        thus       to
limit motion.
        The experimental                                    brace           is made                  of duraluminum                             bands              one-eighth                of ann inch                 thick
arnd three-quarters          of an inch wide.   It consists                                                                of two lateral   uprights,    following         the mid-
axillary    lines from a point       three to four inches                                                                 below   the level of the inferior         angles    of the
scapulae      arid extending      downward    to the level                                                                of the greater    trocharlters      (Fig.     15). These
uprights             are connected    posteriorly                                          by two             horizontal     crossbars,  the one at the top stabiliz-
irng the           upper    end of the brace,                                        the     lower             one crossirlg     the low back at or just below        the
level       of the            posterior               superior               iliac         spines.           Both         of these              horizontal                strips           are         bent      to     fit the
contours               of the             back          arid         are     tilted           slightly              to make                 their        surfaces             parallel                 to the         sacrum
arid      thorax                (Fig.        16).
          At the              lower          erld       of each              upright               is a small              padded               disc          so mounted                   as to rotate                 in the
sagittal   plane.     These                             discs       prevent    undue    pressure                                      on         the trochanters                           and          also serve   as
the points     of attachment                                     for the lower    abdominal                                      straps.           Since   they                 are        free        to rotate,  the
lower            straps           can        shift         their           direction                 of pull         as the             position               of the           thighs            changes             during
i)endirlg            arid         sitting.
          The         abdominal                       pad          selected                is of the              large         semirigid                   type       (Fig.          17)         extending                  from
jrnst below      the xiphoid   process                                              to the top of the symphysis        pubis. It is secured    to the
uprights      of the brace   by three                                             straps    on each side, one at the top, one at the level of the
iliac crests,     and one extending                                                from   its lower  corner  to the disc on the upright     over the
t rochaniter.
          In       ann attempt                      to test           the         efficiency                and      mode             of action                 of the          abdominal                     pad       on an
experimental                        brace            the        force             developed                  between                 the         lower             crossbar              arid           the      posterior
superior              iliac        spines             was        recorded                   on       the      same            subject               under           different              conditions.                  Large
arId     small            pads          in various                 positions                 on the           abdomen                  and          with         different            methods                 of attach-
merit          were         investigated                       both         during               forward             bending                and         slumping                in the            sitting           position
(Figs.       18 and 19).
          With    a small                        pad,          the         lower           the        pad         was         placed             on      the        abdomen,                     the       greater            was
the      force           developed                   between                the       lower            crossbar               and         the        posterior            superior                 iliac      spines,            as
might         be expected.                            With           a large               pad,        unyielding       attachment         to                                 the brace    uprights                            by
three       straps  proved                           more          effective               than        an automatically          adjusting                                    method    of attachment

VOL.     39-A.      NO.         1. JANUARY              1957
1 2-1                                                                                1’.    L.       xon’rox              .-‘uND     THORNTON                  I3tO\\’N

(‘n)rnl)ose(l                     of       (‘n)r’ds aunt                       l)111l(’S.              Flnis        latter           arrangement                     conisiste(l               inn a-       series            of         )tnlIeyS
sen’u       t’e(    I I n ) t Ire i )t’ace                       in )t’ig1it               S ILt     1(1 t Ire .si(les             of t he pads.               ‘Fine        Pa(l     \\.5           sennnneti          t n) I Ire            brace
0   )t n (‘ti      ‘In sin In            I)         i’itti     t ii t n         a     l)in’(’(        0   )! n’lotheshi  nne alt-ennnat-elv                         tin tough      1-lie l)ttllYs     n nn I lie    Pa(I
an no I n )t I 1 1ne                   ot)n’igln1.,             L5        :1    1nt’e        is      I)i-5S(( I t lnn’()uglr t ire (‘‘(‘let                       s n d’ nu sun e. 1          sun’li nun n nnn’n’anrge-
urn      t nt. t inn     .        chat         i n)t nsili1)         01         1 Inn       p:ui          an i(1 I )n’ti((         \\‘nts   t nn nt   fixed        I nit. n’n nt l 1 sIn ill- as t I me t’ l         41i(I
tinn’ough                    t lie I)ltlI(’Ys. I )tnn’inngton’\van’(i l)enn(Iinng or                                                                  slunlpinng,                  (Ire (listnnnn’e bet                        \\((‘ti              the
I )n’an’e arn(I t me l)it(I innn’r’eIS(’(i                                                  inn tine            lover         l)elvic       ant         ann(l dect’ease(l                      in      t ire lnp)et’               1 Inoracic

               :1)l):Lr:Lt    115 tlSn( I I 0 innvnst         igatn’   t inc sPn(nI      vitin      \Viii(’in   Prssur(          is huilt-   LII) ainnl time aiirotrint       of force
           inecessarv         to l)rnhimn’(         nhicoinnfort        at various           locatiorns        ozn tine iau’k. \Vithn time subject pr1m’ witiniin
           tine frainre,       t inc 1)r(ssur(          mon is :uljusted            over       the (lesire(1         locationn,      iii this innstain(’e     tine left l)sterir
          sup(’ri(    )r ilit(’     51)iInt.    lInt’ ren’ornliiig        device,      nnnounnte(1 on a sivivel                 oni t he end of a tinr(’a(Ie(l          roni (‘arm I n’
          anlv:nin(’enl      nr retracted             h    t inroing       tine ro(1. lor          this exp(’rinir(’nmt           the force      oti t Inc l)r(ssurr(      sln(x nv:ns
          ren’orn Inn I fn r ever            n !u:irt   cr i li(’ii n )t a(1VaIi(’e       (See Fig.           I -I).

portions,                     with             coiisequenit              (linllinnutioni    of pressure      over   the posterior     superior    iliac spities.
          It-                          (‘OniPllt(lC(l              tintt tine J)tCl sirould        be as low as possible       arid that- a large      pad fixed
i)’)’ tlit’eC                stl’ibl)S            \\5          tine most        (lesilable,   although     its superiority      over  a small   l)ad     was nip-
l)ttn’ttit-            n)nnIV inn               tine         sit-tinng              position.                   .As i)re%’iously               rnoted,           w’idespread             support    of the abdo-
rneni           inas         SOnii(’           irllnlol)ilizinng                           efiect              onn tine lunibar                spine          1)3’ itself           as shown     by the effect   of
the         \Villianis                    lordos’ns   i)ra(’e.
             A cinest                    str’nrI) of t\VO-ini(h                                     webi)inng             is attaciie(l               to tine top               of the              upright-s             its            tetisioti
adjusted                     so        tilat            it    i)e(.OflieS                  taint         ilexioti
                                                                                                          as          OCCIII’s   anal  yet                                it does           tnot.      constrict               the           cirest
vlnile             the                                  iS stanntlinng                      01’ iS sit.tinrg      erect.
            ‘I’iiis           experinlenntal                              1)race            iias the      follovinig       advantages:                                    (1)      By        tine       elinniniationi                     of the
l)111t5l)itLl                     uprights,                      the           shifting               of the            point         of maxinnum                     pressure                during             fiexioni                cannot
                                                                                                                                                      TilE      JOURNAL             OF      BONE          ANt)       JOIN!’          SUlinrEIIY
                                                                             IMMOBILIZING                                     EFFICIENCY                     OF     BACK         BRACES                                                                  125

occur              and          the          immobilizing                                     effect                   of the          brace             is maintained                     at      the         desired             level        i)y      the
crossbar.                  (2)         The            extension                              of the               uprights                down             as far         as the         greater              t.rochaniters                 provides
a relatively      lon’ point                                     of fixations     for the inferior      abdominial                                                                 straps. Sinnce this low poinrt of
fixation     is at tue axis                                    of rotation      of the pelvis     oni the thighs,                                                                the lower    straps     tennd to keel) a
(onistannt                 tension                   in     either     the sittitig    or standing       position                                                               provided    that     the lumbar     spinne
is niot          flexed.               In       the         erect                standing                         or sitting                  positions             the       brace       exerts              little      pressure              and            is
comfortable.                   Lumbar                                  flexioni                arId slumpirng     in the sitting    positions,     on the other    hand,     are
attended                   by a prompt                                 increase                   of tension  inn the lower    abdominal       straps   arid a sharp     rise of
lressure                  on       the          posterior                             superior                        iliac     spinles             (Figs.         20-A         through                 20-D).

Kirsclnncr-ltTire                               Tests

             Unfortunately,                                     the              experimental                                 brace           proved              difficult           to test            by      the       Kirschnler-wire

                                PPISSUPE       ONT3
                          FORCE- D5PL,ACEMENT-    TOLERANCE


                                       2a                                    ‘                              .-.                L4               SPJNOUS                                   POC55

                                       z                  g;;%/                                                                Dio              SPINOUS                                  POC33

                                       _j                                        2      4              (.         7      S

                                       01                                                             I

                                       hi                                              I
                                                 Di                              /                          #{149}-_.          L4              PAkA5                  P1 NAL                           MUSCLEIS
                                                          .vj                                               O”O                Dio PAIR.ASPINAL                                                        MUSCLES
                                       Lit’S                           a         3      4                         ,
                                       LJs                                             p
                                       LLJhc                                     / /
                                       r,_,)                            ,l           /#{149}

                                                                   7/                                                          POST                                SUP                 SPINE
                                       2O                                                                   ._.

                                       Li                                               ,,                                     BELOW                              P051                 5U P                    3P1 N L

                                                                DI5PLACEMENT                                                                   IN         Y4              INCHES
                                                                                                                                       FIG.         14
       Results            of    tine        experiment                     with   the apparatus                                       shown          inFig.          13. Pounds            of force             are      plotted       against           ad-
vancemennt                 of tire             pressure                 foot.   The slope     of                              the      curves          indicates          the    speed          with         which        force      was       built      up
at various                locatioins             on the subject’s                                   back              as the recording                   device      was advanced.                     The      end point           of each           curve
indicates            where              tine  force      became         intolerable.          As might     be anticipated        the force      is riot tolerated         well over
bony         l)ronsinreirces,                PntrticUlarl’         over      the fourth         lumbar    spinous      process.    It is well     tolerated,      however,     over
the      paraSl)ilial                muscles        at this     level      which        is the site planned       for the application         of force with conventionnal
I)races.           Tine        fllOSt     rapid inncrease           inn forte        occurs     with   the pressure        shoe located    just      caudal    to the posterior
superior            spine.         The          meager                 soft           tissue          covering                 this     point        and      the rigid         pelvis      are of course                 largely          responsible
for   this result.      However,                                  in atiditionn it was noted           that     when      the shoe was at                                                        this    location,     it did not show
a teindennc’       to slip cephalad                                  off the posterior       superior       iliac    spine    with resulting                                                        decrease       in force  as was the
case       whnenn         the      pressure                     shoe was located       directly       over this bony prominence.

VOL.       39-A.         NO.     1, JANUARY                        1957
126                                                                   P.   L.   NORTON             AND        THORNTON                      BROWN

technique.                      Ins order         to     insert            wires         inn the      left     posterior    superior                               iliac spine                   and inn tine fifth
lumbar               5l)iniOlIs                                tile        lonver        cr’ossi)ar          of this i)race     had                           to      he offset-                 at- these   points
( Fig. 2 1 . Fhus    )  (‘n)nntact of the (‘rossi)ar’         with orre of the posterior       superior    spines        was                                                                                                  dim-
itrnitd(I, atnd the support         vas     I’oi)be(I of at least       some of its effectiveness.       To be sure,                                                                                                         other
i)n’t(’dM \Vdt’t’ ItlS() nilodified     but     it- is unlikely    that    their effect. n’as materially          alt-er’e(i                                                                                                  ( Fig.
             iIhe           (fi(1(ts      f      tue         \‘ar’ious             suppoi’ts          tested              during              forward                     i)eni(hnng             fronn            the           erect.
stanndinng               positionn            annd also)          (luring          sitting      were         compared.                   I)urinig              forward                   betiding               tine      cli ects
\\‘en.e       as      fol lt)iVs
             ,t1     1/ic      fifth     iuiinbai’           interspa(-e            (Fig. 23):               All of the              supports                  caused                  slight          flexioni              inn the
stanrdinng               j)Osit-iOtn          except             for  the          experimenstal                brace,             vhiein             cau.Se(1               extension                  ins bot.ii               sui)-
jents,          ann(I         tile     Goldthwait                     brace,        which          caused             fiexioni        in onne subject                             arid          extennsionn                  inn the

                                                                                                                     I)rawinng     of the      exl)erimental           brace      on tIne skeleton.
                                                                                                              By     eliminnatiing         1)niraSPinnnLl      uprights         all the       force      ap-
                                                                                                              plit’(l to tine i)a(’k i)V tine a)pntratus                      is con(’entrated             inn
                                                                                                              the      region        of    tine     1)osterior        superior          iliac     sines.
                                                                                                              \Vhereas          conventional            I)a(’k     sup)Orts         s(’(k      to avoiti
                                                                                                              pressure          over bonny pronsinnences,                 this brace      is dt’signreti
                                                                                                              sl)ecifi(nLlly         to 1)r0t1U(tn       unncolnnfortai)le         t)r(ssur(’        over
                                                                                                              tinese     inonnv                    ins 5()O1i as tine allonvahle              hinnnits of
                                                                                                              flexion        are    excee(lcd.        ‘Fine lx)sitionn         of thin’ ah)(h)niiinal
                                                                                                              l)ad      cannot        shift          sinnce        tine      stral)s       are      arralnge(l              to) pull
                                                                                                              upwar(l,             downnward,                  aln(I laterally                   vitinout               tine nneed
                                                                                                              for      peronneal         st i’ni)s      (n’onit       rast       t mis        it in 1ig.s.             2 arid     3).

  BACK                         VIEW                     FRONT                          VIEW
                                               FiG,     1.

                                                 FI(.        I6                                                                                               Fnn.         17
              Fig.       16: Back    Vi(’iV      of tinn nxl)nrinnnt’ntal          brace     oni a subject       showinig       how tine lower                                           crossbar             rests      just
          caudal          to tine posterior          superior      iliac spines.          The    upper      crossbar        lies three     inn’hes                                       below          the       inferior
          anngles      of the      s(’aptilnie.      1-lotin nnre innt’linneni slightly           so that they lie p:irnnllel to the                                                   body          surface.
             Fig.       17: Back           vies.   of n’Xt)(’rinienntal        i)rniCe showinng        lateral       uprights,      trocimniniteric                                        l)i(ls,        Ul)l)          and
          lower       n’rossi)ars,         large   sennnirigid     ai)(lolnninral       pad,    arn(1 chest       strap.

                                                                                                                                   THE        JOURNAL                OF         BONE       AND          JOINT           SURGERY
                                                 IMM()JIILIZING        I.:FFrCIEXCY               OF   JIACK   ttIt(iES                           I 27

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Vol.. 39-A.     NO.    1, JANUARY             1957
 125                                                                                                     1’.      L.      xoit’rox                      .&ND            THORNTON                               BROWN

n)t     hen’.         .\.t          3()            (legnees                      n)l     forward                           bcnn(linng,                      all        .sl1p)on’ts                      cause(l             SODid                limitation                        of inntet’spa(’e
flexionn                   (‘X(’dj)t                      l’nn’             t Inc        .Jeet                    t      i)n’a(’e               in          onie             sui)jdct.                   (P)      ,     inn     \VilOm                   ini(rease(l                     innterspa(’c
flexionn               n )n’(’nrn’n’n’n                   I . ‘llne                    nn’i nnf’on’n’cd                          laylor                 i)n’ace                cntllse(1                 tine greatest                           limitat           ion             of rrrotioin           at
1 his          levnl                 i in I n             t In       sini        )jnct                     I in t he suI)Je(’t.s                                  i   nn \vln()nl                  1he ( oldt-irnvait                               and           tile         (‘xperinncnit              al
I )t’IL(’P           ctt1sc(                   I    nxl         (   ‘ini      n)i 1      (    )I I liP                I nnrnil )osnu’n’ai                       i nit (‘r’sl)nLce                      iU     tlid       stann(litlg                 position                  ,    I lie (‘fle(t         of
t   Ire      bn’an’es                    a.t         t his             level                 n tuning                    3()        (Iegn’ees                     of fon’nvard      lsenidinsg                                     as              somevhat-                         atnonnalous.
(     ‘n nnsinien’nii                    )le         i nt (nsl)ann                             niiot            i( )rn was                  l’n’nnil               t (‘(I i)v these     sup)Ot1                                       5     l)ut         Sitice          it Stt1’t((I                f’norn

                                                                           i’nn;. 20-A                                                                                                                                             Fin. 20-B
             1’ig.         20-A : I3chnavior                                     n)f    t inn nxl)nrinnl(nnt:tl                                hrnu’e          onn a subject                       inn the            stnundiing             1)Ositiofl.           Large             ahjtlonsinnal
       l)1(1     nxtn’nnds                         fronin           just         hnInniv              xitilnoid                  l)r(’(ss              to       the          5yIn5)hysis                    pubis.
            l”ig. 20-13 : Inn forward        I nnidinng.     I inc ln)wer    stral)s  tightein                                                                                                  pronil)tly.                Note            tire inderntat-ionn                       of tire skinn
       n’:ntrs(’(l I )s t inn Inavnr  st ran    i I ni loivnr     n’rossi )ar nit :ipproxini:ttel’                                                                                                            :30 (legrees                of forward                 benndinng.

a- 1)Ositionn                         n)l eXt(’nnsionn,                                       t lie            finral            positionn                after                  30 degrees                         of forvard     fiexion     was (lOse to
tue          Zd1’()               l)ositionn                        ; I hat                  is,         the            i)osit           ion           of this                  interspace                         while    the subject     was standing
vitlioi.it                        sinppon’t.                          Inn other’                          words,                    the           anisounit                      of        flexioni               nvhich    had taken      place   between
stann(hnrg                         and                3()           (Iegne(s                        of         forward                         fIexionr                 svas             lininited               very              little,            but          the             arc       through
\Vliieii             it-          1111(1 occur’n’ed                                    iii(I              shift          eI         tovards                           extenssionn.
               .1 t tine foui’th                                    Inunbai                        interspace:                           \lost-               of the             supports                       caused       some                     flexion                  in the stand-
org          positionn                              (Fig.                  24)           (X(’ept                        inn      one            sui)ject                       (.J). The                       explannationi                         for the                    tendency     to
extenisiOtn                         of         this              innten’sl)ane                            inn this                ini(Iivi(luai                         is      riot            clear.          At        30 degrees                       of forward                        i)endinig
all        apparatus                                  cahlse(l                      5()tlld                linnitationn                           of          flexioni                at         this          inter’space                         except                for         the       ,Jewett
i)r’a(’e             inn onne                      slli)j((’t                     ( P ) . I nn t his                             inrst-annce                    flexioni                   at      this          level             was            increased.                        The        experi-
metrtal                    l)n’It(’t’ lit                       t Isis        level                  pen’fn)n’med                           rather’           n’elI except. on subject                                                       I. Inn his case study                                      the
moving                      pi(’t ur’es                         n’evealed                           t hat              tine       lower                 (‘n’ossi)ar  was located    too                                                    high with the result                                       that
(liming                forward                              i)enldinng                         its         for’n’e                              i)n’ought-                     to        bear             above               this           interspace.
               At          t/l(          t/Iil’(I               lninthai’                    iflt(1’Sp(l(’C                        (Fig.               2;):            i1\Iost              of the              supports                         caused            extenisionn                      in the
standing                           POSiti01n                          \vhi(’h                      l)etsiste(l                      01         e’eni              in(I’eased                           slightly               when                 the       sul)ject-s                    l)etrt      for-
ward      to 30 (Iegr’ees.                                                   Hen’e                   also,              h()we\’er’,                      there                 were              some            rather                striking                   and unnexplairled
ex(’cptionns    I n) I iris                                                gennenal                      finndinng.                      Presumably                                 at          this          higher                 level     the                force exerted                          by

                                                                                                                                                                                                   TIlE        JOURNAl.                   01.’    BONE        ANI)             JOIN1’        SUR(;ERY
                                                                               IMMOBILIZING                                  EFFI(’IENCY                   OF        BACK             BHACE5                                                        I 29

 ninost               S(nl)l)Ot’tS                    \.a.s      SitthUi(tit                   to     cause             extenrsion.                  \Vhein            this          n’as       of ann lnlneomfortai)le                     (legree
 as         \\5         tine             (‘itSd          ivith          tue           Plaster              jacket,                 the       extenrsionn                n’as          niost          niarked.
                   I tn the              sit      I   inig posit               ioni       t inc foiiow’inig                          (‘fTe(ts            were         ol)serve(1                  ( Fig.       27)
                  .   11    1/iC         /P’           lii,,r(ai            in/erxj)(1(’e:                  All ntl)l)an’atlts                      (liminished                      I he amount                   of flexioni         occurring
 nit Ihis                   leoe1              inn hot             in t Inc           ei’cr         t anr(I          shlnnil)ed                 posit       iotns.           ‘Iiie          exl)en’inietnt           nil i)rnue         riot. otily
 1)t(’\’(tnt((Iniiot.iotn,ion                                                  niainntaitned                        sonic           (‘Xtetisiotn of tints joinnt inn hot In tlie erect                                                   ann(I t he
 slunlpe(I  posit ions.
                  At        t/1(         fourth                 1UFfll)a-1’            iflt(        r.’p(we:                 ihe          sanne          tetn(lenn(’y                 to       limit   flexion was apparennt
 ‘iieti               till tvj)eni                    of appan’atus                       ‘dt’e            vorti.              however,                  the       effects             at      this level seem iniconisistenit

                                                                Fin;. 20-C                                                                                                                        Fr;. 20-1)
              Jig.         2(1-C:  \\hnenn tire suh)je(’t      is sittinng                                          erect,         tine    lower         straps        are  siring but                riot excessively             taut.   Their
       ternsioin             has nnot (‘hnannge(l nniaterially         froni                                        that       inn the       stanrdiing           positionn     I)ecause               their  points          of attachmeint
       to         tine      h)race          nnre at             tine nnxes of                  rotationi     of             tine hip joilnts.               Furthermore                      their     1)osition        is   sucin    that   they
       frill        unto      tine         innguinnal              folds  henr                  tine subject                  is sitting.
               Fig.         2(1-1):            Wiieii            the      sul)ject attempts                            to      slump     as is shown                    here,  it is apprirennt-  that   the backward
       rotation                of        tii(’    l)elvis              an(l tue lumh)ar                        flexionn            which     ordinarily                 accompanies        this movement      is largely
       (‘hinnulnat-ed.                    \\iieni        the           s(li)ject’S              position            here          is compared           with             that in Fig. 20-C, it is apparent            that
        lit t he (‘inannge                  inn 1)ositiorn               of tii(’        pelvis            ann(1 1over               trunk         has     occurred.

inn SOflle                   innstannces,                         \vilenn            compared                       with            those           at      the        irnterspace                    below,          notably           w’ith the
reinforced                          Taylor’                    bra(’e          arid            with         the        plaster-of-Paris                              jacket.               This       is probably                the    result. of
(hisplnn(’emenrt                                of      tile       skins         in      the        proximity      of the wires with resultant         discomfort.     This  was
a variai)le                         nvhich                was       difficult                    to control.     The experimental      brace     at this level,    as at the onre
l)eIOW’,                   nniainrtaitne(l                        a posit-ions                     of extensionl     with  the subject    erect,    i)ut with slumpinrg      the
interspace                           moved                     through                  a considerable                               arc        of motion                    to just              i)eyonnd           nneutral.
        ..lt the third      lumbar      interspace:       As might       be anticipated,       all apparatus        were   effective,
tenr(Iinng      to maintain         a position        of extension       with   the exceptions        of the \Villiams           brace,
n’hich       Permitted       slight    fiexionn during         slumping,      annd the .Jewett       brace,    which     permitted
slight      flexionn during        the erect     sitting    position.     With     several   pieces    of apparatus       extennsionn
inncrease(I                        nit         this            level         during                   slumping.           This     effect                            was     most  noticeable        with    the rigid
 l’avlot                   i)raee              vhich               n’as     observed                         to cause       considerable                                 localized    pressure      at this level as
tine         slll)jt’(’t                 assume(I                       the  slumpe(1                         J)OsitiOnn.      Inn spite                             of the variai)le       effects   rioted    inn this

VOl.         39-A.          NO.          I, JANUARY                     1957
13()                                                                 1’. n.. NOItTOX                    AND           ‘rHonixTox                nnIu)\\x

                                          Inn,. 21                                                                                                                      I’m.. 22
      11g. 2 1 : ;nn I nor                    n 1 1I in nXl )p’j nnin’n 1 :t I I )ra(’n’     mm H hifie I n)r I (st inng iv it in l’irsn’ini           nn’r-iv irn nina knrs.
 ‘l’hnc lovnr       nr )si ar hn:ns I )OO1n tnt :ts\:n\             over      I Inc left I stnrior          superior        ili:nn’ 51)110’ :iinn I t hn(’ liii) 1-lime. ‘l’hne
 ( Iefen’t   hints I )Pn’l n I rin lgci I I ‘s :n rn’(ttnng1nl:n r I1J(Iinl )nr i )n1 it Inn)st(’rin)rlv           inn such       n fasinin )Ii I hat n’oint ant is iiit      In
 iv it In I Inc 1 x Iv n)nn lv a I t inn . l’vn 1 n )f I hnn             ssl ):n r. “l( )t S ‘tnt I I n 1 In . ‘rn ssi :n r :1 lln av t Ijnnsi niienn t ( of I hnn       i II In
 of t hn(’ g:n.)S I lnronnghn           hnichn I Inn ircs       inn nyc.

       I’ig.     22:      1nnstnriur      \in.\-                of    t inn ( ,))I(ltinv:nit        h)r:L(’(’ titer    is’iing     innodified       or use ivithn l’irschnnncr-irc
  iniarkers.            I inc let t l )r( JO ‘nt           in   ni :n I in I I lie Inninl(ll(   sn’gina’nnt   n)f I lie lini(lnlle     (‘rn)ssI ;or anal  t ohnort segnnrennt      01 t Inn
 left vert in’al UI )righnt hn:nn                           I nncnn mnumn n’n I. .& ( -shn:Ll)n’ I iniennii )(r                  hnich nloes mont (‘onnt ut t lie surface          of t Inn
           hnas i)nnnn nnlnln’nl Inn
 i)n)(I#{188}’                                             rntnnnn          rigili1                                                       tine                     thin’
                                                                                           annnl to tinrnnisln a 1)nnilnt l#{149}nnr :ott:u’hinnnn’nntnnt#{149} ln’ft nininldln’
 st rap.

  EFFECT                                OF                  S LJPPOT3                                                                           L-                             NTERSPACE
                                                                               [OkWAPD   5LND
                                                                                   2 MODELS
                                        h (          ) I                      J                                                    M()JH                                   Nil
                                                                      L4                                                                                            L3-.i
                                          5TAN              DINr                                       DIN        G                   5TAN            DING                           bUNDI      NG


                                              3?I(                                    S       2 IC)’       :                        .4 3 2      I   OI       34                  4   T   Q      2 34   .56’7#{244}9eTh

   NO          SUPPOF..                                                           .       .   .   .   fTJ
   LXP[PJM[NTA                      L                      11                                          1]
   (J-4AI              bACK
   GOLUTOWAI                    f                                                                      1
   J [WElT
   PLA3T[.             JILKET
   RiGID          TAY1o
   FLEX.          TAYLOU
   REENF          TAYLOP.

                                                                                                                                       4--           i’

                                                                                                                      5TANDING                                      o
                                                                                                                      FLLX0N                                    -   -

                                                                                                           JIG.       23

                                                                                                                                     ‘i’lIl-:       .JnORN-I.             no   lnnxn:    ANI)     JnnIN.1’     snntn;n-:nt-v
                                                                              IMMOBILIZING                                     EFFICIENCY                                 OF           BACK             BRACES                                                                              131

    Fig.     23: Ef1t            of various           i)a(’k supports         on tine fiftin lumbar           interspace         in the standing             positioni      and   inn 30
nlegrees       of forward            benndirng.       The zero        line for each       sui)ject    represents           the angle       formed       between          the wires    inn
the spitnous          pro(’ess        of the fifth lumbar               vertei)ri     annd in the left. posterior superior iliac spine with the subject
ill the     stannniinig       l)OsitiOli      without        support.        The horizonntnnl      bars      extending         to the right or left from the zero line
represn’nnt      tine chaniges           inn this angle        due to bending           without     supports          (first   horizontal        i)ar) and due to standing
annd benndirng          while       wearing        various      types      of support       (other   i)ars).      All values        represent        averages         based     on four

to eigint               (I(’t(’rniilnationns.

                               EFFECT                                       OF               5UPPOT3        L-5 INTERSPACE
                                                                                              FORWARD     BEND
                                                                                                  ,3 MODELS
                                                  nil          B                                          M(-IH           I                                                                                    “lCD          IL

                                                        L4-                                                             L4-5                                                                                                 L45
                                        TA?-NG                      bEND          NC,               STANDING                                         bENDINIG                                          ST/NDsNc,                                  bNDI            NG

                                                                                               i#{149}                                                          i3Q
                                       3    -i9                          .#{149}2V45#{149}                        234                              ..‘iOi           34         54789            .4        I   OI        34        5          )l                  234

           ...)       J-t-kI                      I                 ___j                                   I                                                -----          -   -I                                                                            -         -- -

                                                                                                                                                            I1                  i                      E:i                                                 ii

                                                                    I                                      b_                                               h-i                                                                                            -----i


                               --L :
                               -                  I                                            -_          I                                   ‘            -        ,-                                                                      4           ,
                                                                                                               STANDING       C

                                                                                                               FLLXION     -p

                                                                                                                                          FIG.              24
              F.f1((t          i)a(’k sup)orts
                                       of            oh tine fourth        Iunsbntr     irnterspat’e        inn the stanndinrg        l)Ositionn     and inn 30 (ltgrt’ns
           of forward         i)ennhnng.     ‘l’he zero line for ean’in subject                  represents         the angle        formed        by the Kirschnner-
           wir(’    iniarkers       in tine spinious    pro(’esses      of tine fourth          anrd tine fifth lumbar             vertei)rae        when    the subje(’t
           ias     inn tint’ stanithitig    position     without       a support.         The inorizonnt.al            1)ars extending          to the left anal right
           fronin tine zero limes reh)resennt             tine (hnninges        in tinis n’nngle du(’ to bending                   withnout       support      (first   hen-
           zonntal      hair) ann(l (hI1(’ to standinig          anini i)enn(Iinng    vhile        veaninng       various     tvl)es      of sul)l)Ort    (other      bars).

experiment-,                                the          (‘xperimenrtal                             l)race                seemed                    to limit                         flexions                 and        to            mainstaini                             a positions     of
(‘xtetisioti                         mor’e              (onrsist-enrtly                         than              the           other              apparatins                               tested.
                  Although                        a study                     of lateral                       1)ending                   was               riot- made,                              it was              observed              that   the experi-
ninetit-al                 brace                 appeared                         to         restrict                   this        movement                                    more                 efficierntly                       than    the others.       The
extennsionn                         of the              lateral               uprights                     downnvard                           to the                     greater                trochaniters                             was largely     responisi-
l)le      for             this             increased                       effectiveness                                (Fig.           28).            Patients                            fitted     with                           this support     frequently
remarked                             that             it prevented                             side            i)enidinig.

P1(’,SSUl                 e Tests

                  A       comparison                               ()f      the          forces                (Ievelope(l                          by              the             different-                     types                of         apparatus                         may      be
Sedtt             mr Figure                           29.     As           nnot.e(l             previously,                          it    pn’oved                             impossii)le                         to        adjust                  the               gauges          on   the
difi’erennt                     supports                      at         (‘Xa(tilo’               tiid         san-ic             level              on             the             i)a(’k    arid to a(ljust      the forces        exer’te(l
l)V iil                t\’l)ds              of        tLi)l)Itt’ttt          us         so t hat                they             \\‘ere            the              same               as    inn tine initial  stans(ling      positionr       mi
ea(’h              test         .     I love’et’,                        Slti(d          tine            significant                      poinrt                     with               regard       to tine force     develope(I         by a
i)ILL(k            5U)pOrt                       used         for          immoi)ilizationl                                    is the              n.apidity                         vith            which               tine           foice                iticreases                dun’inng

VOl..      39-A,               No.      1. JANIAIIY                        1957
132                                                                   P.       L.     NORTON                AND       THORNTON                       BROWN

the      act       of forward                     betiding,                the         values           obtained             are       at        least        an indication                 of the          compara-
t-ive     efficiency                   of the          various                 supports.                Interestingly                      enough,              the speed                at which            the force
increased                 was          not      necessarily                        related            to      the initial pressure      between      the brace                                                and the
back.          This        rather             unexpected                         finding            was       apparently   related    to differences     in the                                              subjects’
spinal          flexion               patterns               and         to         differerlces             in the mode     of actions    of the apparatus.
        Although      the                        results            of these             experiments                   do riot show clear-cut                                    superiority              of any one
support      as regards                           force           produced                against    the              low back,   it seems    fair                               to say that              the experi-
mental             brace              produced                relatively                   large          forces        at the             lumbosacral                     levels          more         consistently

         EFFECT                                   OF              5UPPOT5                                                                                               INTERSPACE
                                                                   EORWARD SEND
                                                                       2 MODELS

                                                                                                   STANDING                                0

                                                                                                   4-       EXTLN5ON
                                                                                                              FIG.     25
               Effect      of back             sul)ports            on     the third             iumi)ar       interspace             in    the standing                #{231}osition in 30
                                                                                                                                                                                   and                     degrees
         of forward               bending.             See        legends            for Figs.          23 and       24 for explanation.                          Kirschner-wire             markers        in this
         irnstance             were      inserted            in    the        spinous           processes           of the    third            and       fourth        lumbar        vertebrae.

than         the        other           supports                  tested.              On these              four      subjects                  it excelled              at       15 degrees             of forward
bending               in onne, at 30 degrees                                     inn two,          arid      at 45 degrees                       inn three.             As regards                the     rapidity          of
build-up                of force              during              forward                benndirlg,            the      performance                          of the            experimental                brace        was
also superior.        Between                            0 degrees arid 15 degrees    of forward                                                           bending,               it excelled            ins only one
instance     (subject      B),                         hut between     15 degrees  and 30 degrees                                                            its force             build-up             was greatest
in three    sui)jects      (P,                         H, anrd B).
          The            reinforced                  I’aylor.              brace,            nvinicii        was        onne of the                      more         effective            supports,            did      riot.
produce                 very          large         forces           inn at least-                  three         of the       subjects.

( ‘linical            Trial           of 1/u Experimental                                   Brace

        Up            to this time                     the experimental                                 brace   has i)een                        used orn about                      100      patients.              In the
majority                of instances                    it n’as prescribed                               as postoperative                           immobilization                         after     spine           fusionr

                                                                                                                                           THI       JOURNAL             01’     n)oNl     AND      JOINT       SITR(JIRY
                                                                         IMMOBILIZING                               EFFICIEN(Y                           OF        ti.-iCK          ntiA(’t:s                                                                       I

                   E FFECT                                              OF          5 UPPO         D
                                                                                          RT5 FORW\R BENP                                                 -

                                                                                                              ONE MODEL

                                                    I STANuiNI

                                                                                                                                        0              STANDING
                                                                                                                                       .-+             FLEXION
                                                                                                                                        4.-.          TEN5tON

                                                                                                                                 lID. 26
             Effect      of l)ank su)ports            inn tine stann(ling       l)ositioni      annd inn :30 nl(’gre(s       of tn)rwar(I       hnnnnhiing onn thin’ lover
         three      lunshar        innterspaces     inn one ones/el.       i’inn’ zero hiln(’ for nanhi inntersl)a(’n’             r(’pr(’selnt     s tue angle     fornnied
         h)’ SUccessive             l)nirS of Firschnner-nsire           niarkers         inn thin’ s1)innous     l)ront’s’s     of tine tinir(1,      fount-in, ainni fiftin
         lumbar        v(’rteh)ra(’        anal inn tint’ left postt’nior          sup(’nior       ilinin’ spilnn’ \vin(’nn tine subject          was inn tine stJnnndinng
         Position                without               support.                See       legeninis     for Figs.     23 nnnnd 24 for further        n’xplannatu)nn.      Note   vaniai)ln’     ef-
         ft’cts at nn(lja(’n’nit initersl)an(’s.                                       Inn tine standing         positionn   (‘xtennsion   of tin(’ fifth     nund flexionn   of t Inn’ fourth
         lunibar   inntn’rsl)an(’    :01(1 vice                                      versa      occurs     with    various      tv1)(’s of nipparnitus.

l)erfornle(1                    for         lO\V-l)a(’k                  (Imsai)ilit mes. It has                                  trot l)eenn inn use                              for        a sufficient                      lenngtls             of time      t.o
(1ra\’ any                    (‘onn(’hnsions                          as to its effectiveness.                                       ( )nslv impressions                                      (‘ann       i)e     reporte(l                   at      tilis time.
       It has i)eenr                               f)resct’ihed                          i)V      several              doctors                  riot           (‘onnnecte(l                   with          tinis            proje(’t,              arid         it. has
i)eenn satisfactory                                    to      1)0th               the          doctor             ann(l         the         patient                  with          but           fenv          ex(’eptionrs.
            Fhe             principal                         (omplainrts                           iiave          (‘onn(’ernned                       (1      )   the            prominnenn(’(’                       of       the           t rochatnt.eric
I)a(Is,        oi)jc(’ted                     to       i)\’       \‘t)meni                     particularly,                      (2)          the            pressure               over            the         rii)s         at. tine        upper                end
of the             lateral                uprights,                     (3) the                  prominrenr(’e                    of the               upper’              erossi)ar                 betneath                  the        (lOthitig,                annd
(4)      the        (liscomfort.                        froni                the         large        ah(Iommnnal                       l)a(1 inn the                    e)igastr’ic                     region              arid       at the             xiphoid
            FiiPse                 oi)je(’tiorns                       have               i)eenn            elm nninrat           ed           ai rnost.              ivit liout-               exrept)monn                     l)y       more                (‘arefnni
fittinng           of       tine          a)paratUs.
            After               sl)inie            fusion,                   ani occasional                            patiennt                inns           tomplainred                       of unr(lue                    pnnre                    over          tine
tennder             operative                       sear.             ihis            diffr(’lnlty                 has       been               Oi)\’iate(l                by bending                           tue          crossi)ar               to         reduce
O’      eliminnate                      pressure                      nn’here             the        bar        (‘rossed                 the          teni(ler             area.
            ‘_l_’\’() l)atienits    nvho ira(l                                           use(l        other              i)nnt(’es             in the              past-          volunteere(l                         that.          this          apl)aratus
ga\’e         t.iidfll     l)(t ten Sttl)l)n)tt                                      .     ,        salesniatn              ,      vlno               (‘ustoninirily                          (irO\’e            hetw’(’enn                   Ilostorn              atn(I
( ‘iiin’ag()            inn t Ire n’ourse                             oh’ iris           work         ,     lund       1 (‘etn forced                         I o take             to I lr(’ train                     iii     order               t o t n’avel           inn
:1 recunisi              )en it           l)Ositioti              .     I I(’        \Vnts         nd)l(’ t ( )          tdSiI         nine ( I nh’ i nng w’in(’n n 1ne                                  mU! I )(‘dti                 fitted           \‘it      Ii t ii(’
experinnnenrtal                           l)nnt(’e,            arid            Ire iias             (‘Onititiln(’(I                to        drive              his       (Iii’      for         eight            mont           Ins.
            ‘T’iie          t   tii(’       nieasu             re        of        t he          t’ll’ect      i ‘er     i(’SS          of      t ii is so ppor’t                        as      i In     moi         )ili zntt       1( )t   n aft-en            spi ni(
l’usionn            n’ill         depend                    inpoti             the         mni(’idenr(’e                 of pseu(larthnosis                                       w’heni           this          bt’ace             is insed               as     ‘orn-

Vol..      39-A,        No.         1, JANLARY                        1957
134                                                            P.     L.     NORTON                 AND           THORNTON                      BROWN

                                                    EFFECT                                     OF            SUPPOQT3
                                                                                         1 MODEL

                                                          STANDING,  NO       3UPPORT                                                                                  o
                                                          ELEXION     -#{247}
                                                          4- EXTEN3ION
                                                                                                          Fre.      27

     Eflects     of hnank sup)orts           on thin’ lower     tinree lunibar        initersl)ni(’(’s       when   tine suh)ject     was in th(’ sitting           posit-iorn.
The       zero    lint’ for each        intcrspan’e      represents          the angle         formed          by the successive            pairs     of Kinschnner-wire
nniarkers      inn the spinious        1)no(’(’ss(’s   of tine third,         fourth,      and       fifth lumbar        vertebrae        and     in the left posterior
superior       iliac 5l)11’ when            the subject       was       inn the standinng             position     without       support.         The    horizontal          bars
(‘xtenn(Iing      to thin’ left ann(1 nigint fronni these            zero lines repnesent                the changes       in these anngles due to sittinng erect
anntl sittinig       inn the slunnipn’d       Psitinn     without         support      (first      ban) anti witin various             types of appiinatus               (other

pared     to the inr(’iderr(e        of tllis (‘Omplicationl     when    other                                                                      supports                     are      employed.                  No         such
comparisons       is possii)le     at this time.    one instance      of failure                                                                       of fusion                  after         arthrodesis                of the
fourth     lumbar     irnterspa(’e      arid the use of the experimerltal                                                                               brace              has          beers       reported               so    far.
           Of some             interest            n’as        a patiernt.                    convalescing                      from            an       attack                  of acute                low-back               pairs
\‘it1l       radiations           of      pairn      (IO\Vti          the         posterior                 aspect           of the                 right.       lonver                extremity               to    the        calf.
He        preferred            a reinforced                (‘orset               to the           experimental                         brace,                stating              that          he felt         more            com-
fortable           inn the        corset           although                      the      brace             did      restrict                 his       1)a(’k          motions                   more         effectively.
Comparative                  standing     arid                  i)enndinlg    roenntgenograms                                          showed      that    the brace     caused      him                                               to
stand    n’ith            the lumi)osa(’ral                       joint    ins extension      while                                     the corset      produced     slight     flexions                                               at
this       innterspa(’e           (Fig.       30).        Although                      the      location                of this          patient’s                    lesions            was       riot     established,
it- seems          entirely            possii)le          that             the         extension                  of the         fifth          lumi)ar                interspace                   associated                  with
wearing            the        brace        ns’as less               favorable                  thans         the         flexionn         produced                         by      the          corset        inn this           pre-
sumed           inrt.ervertei)ral                  disc        lesion.


            mr this       )reIinlninnary               r(’port.             tine (lata              are      inna(Ie(fultte,                   ani(l there                  were           too      many            te(’innli(’ntl
faults        to l)(’tnllit  final (‘onn(’iusionrs     Its to the                                         immoi)ilizmnng                       effiemenn(’y of back braces.                                         Nonet-he-
less,       points      of (‘Otisidenal)l(’     inntenest    have                                          been     raised                    about      normal   luml)osacnal                                          mot        mon

atn(I      tine (‘hI(’(’tS of i)races       oti it.

                                                                                                                                       TIlE         JOURNAL                01’     BONE          ANI)      JOINt’      StiLUEIIY
                                                                                 IMMOBILIZING                                   1:FFI(IEN(Y                             OF        BA(K          BHA(ES                                                                          I 35

                                                                       Fin;.        28-A                                                                                                                    F’nn;. 28-13
              (         Olnil ):nri sn nn of sinle             1)elnnlilig inn (Fig. 28-A                                          ) t hn(’ n’Xperi Ini(’nnt il I racn’                         :tnn( I ( Fig.        28-13)         i in thin ( n1n It hnwait
         I nr:nn’n.            1ailurn              nf t Inc lint tt’r to grip tint’ lalvis                                          is t)1 Vin)US.

               1’cnn                   inn tire              l(’\v        Stli)jt’(’ts              studied,                       a wide                vaniatmoni                   of niotioni at                       tine      lnnv(’n’           tinn’et’       inter’-
sl)tt(’cs\va,s f’otnnnd. ‘Fliis                                                  van’ietl  niot onily as r’cgan’(Is tine range                                                                          of nnovenl(’nnt,   but also v’nth
n’esi)e(’t to r’ogressmnnn                                                     of fleXionn   (limninig tire (‘out’s(’ of fonvar’d                                                                                      l
                                                                                                                                                                                                          l)(’nn(linig. on (‘xusnl)l(’, one
sui)je(’t                      it           Ii tigist                  lnannstn’inngs                     anti               l)0()1’          al)ility                to          i)enld        for’va,nd                 cxlnil)ited                  1110(11           DlOtt’

ulexionn                      inn his ln)w(’r’Iunhi)ar’                                          ntrtn’tnltttionnsthan                                         a snni)je(’t-vitIs                            loose             l)ost(’nior’ St.nUCt-Inr(’s
\Vli()            (‘(    )ln 1(1 t ouch                         tire       floor.            .\.gai        ni , sonic                   sui )J e(’t.s              a)pear’ed                     t o (‘Xl)enl(l                nil 1 n )f t he               available
t’inige                  of’        flexioni               inn t heir’                 Ilnfl11)()sa(’nfll                      jomnnts              (luring                the        first        30       degrees                 of        t runnk         bending,
viniIe                  in      ot lien’s,                 flt’xioti             at        t his         level               o(’(’Inn’n’c(I inn a more                                     gra(hmal              nnannnien.                   The        iflIl)reSsionn
\\.as         gamrnc(I                      that            (Iefiniite                 flexiotn            l)att(’rnrs                      exist           w’hmn’h               nsav         vell         be       of      sonre             (‘linri(’al          signnifi-
n’ann(’e.                    Fn)n’ innstani(’e,                         it- vouid                  seem            reasonnal)le                          to       assume                   inn the       ti)sdn1(e                 of back               symptoms
that              t-li(’         SIli)jd(’t                 vitii           till’        letst            lunlli)an                  rnotion                   during               forward              i)cnrdinng                 aul#{128}l be less                     sirs-
n’(’ptil)ie                     tO          IO\V-i)nLn’k                   strain                or’ to           \Vefl1’              arid          tear          (‘inannges                  than          tine         others.               Similarly,                      t.h(
inntli(’at.ionis                            fOr          5l)itIe           fusion                after            (lis(’             surgery                   anid          tine          inr(’i(Ienr(’e            of      i)seudarthn’osis                            after
finsionn                     nnigint              vell           differ’            in     t is(’se         t    \V()         t ypes.
              Sitting,                        even               if’ eren’t,              was            found                to       be      associated                          witin        sul)stanntial                     flexioni            of the           lower
t’sV()       lunsbntn’                       initersnl)ares.                          Inn fact,             flexionr                   was          greater                  at     the        fotnrth           lumbar                  inntensl)aee                 in the
slunnl)(’tI                         I)OSitiOti                   t-hann          it                   vinens                 tind       sanne               SlIi)ject                was        stann(linig                inn niaxinnuni                       fornvanl
flexioni                 .     If      the           Ohe(’t.               of t reat.mennt                              is      to      immobilize                            tine         lumbosacral                       spitie,                either          sitting
Inntnst                 I)e avn)i(led                         on t lid                ai)l)anat            us       eml)lOYed                            for      imnnobilizationn                               must-            i)e effeeti\’e                    ins this
Posit          ion
              line                  a(’tioni                of         va rious                  ba(’k           slnl)l)orts                     tnti(lOini)te(IIV                           ‘anmes          a(’(’or(Iinig                     to      the         lullli)ar
flexionn                     l)tttet’ni.                  TIO\Ve\’dn’,                     these            studies                    inni’e            riot           progressed                    sufficiently                       to      elin(’i(late                  this
I)Oinit.                 I tr        ntie          Slni)jent.               vith      nninninial                         motion                     of      the          lt)\VeI       linmbar                   inntenspa(’es                     (lun’inig          trunk
fI(’XiOni,                     n’n)nnpar’ativ(’lv                              little     f’or’n’e                 vas               (le)’(’It)I)d(l                    by         the   \‘armorns                  supports                    at     tine        ilnflli)O-

sa(’nttl                 leV(’I
              (‘lose                   n)l)S(’t’\Zitmn)ni                       of tire 1(’tioni of long                                                 i)a.(’ksupports                              (hIring             fonvand                    bending                   anl(I

_n)n..       39-A,              N) n        1, JA NIARY                     1957
136                                                                      n’. L.            NORTON                          .NI)               ‘rHonIN’noN                         nitnO\VN

                                                                                                      FOQWAkD                                             SEND

                                                                              INCPEMENT5                                                            or            “PPESSUkE”
                                                                                                      FPDM                              SUPPOP.TS

                                                                                                                       4                 MODELS

                                                       MODLL                           :                  P                                    H                                  D                              B
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                                                       TAYLOR               LBS       [ i[1                                             L45                          L4-5                                L4.

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                                                       TP.UNK J:                                     I5!C4                          0 I3O45                         0      I5f                       U r545

                                                                                                                                    Fn;.           2U

     ( ‘n OniI):trisnfl     I 0 )t tn)rn(’s  I run lunn i again nt t hnn 1n)\\ I nan’k inn four suhjen’t              s I y various         tys’s        of a1)l)aratus.          ‘line
vn’n’t in’ni 1 n’olnnnnin            nt 5(’1   it I inn . i nn( nn’Dsn n nf t inc fn nn(’e    1(’(’Olnl(’(l vinenn t inn’ sui )j(’(’t 5 V(’1’(’      i)t’In(hilig      fo,’ivan’d     to

 I a dn’grn’es.          3() nln’grn’n’s, :nnnnh -15 n lngrn’es.       ‘hun 1 lank n’olunnsnns r(’l)r(’senlt       thn’ nniaxinnnunni        forn’e (levelop(’(I             on ea(’hr
sui)j(’n’t         for (‘Dcli n)f thin’ I hnrnn’ 1ositin)1n5.            ‘Finn’ tomes      n’xn’rt(’d     i ean’h nippnirnitus       in the stninndinng positiorn are
i ntlin’at n I I ) I inc nnunnnr:n Is i 1 I I inn . Inacr             In ft-hen n ti n’orni(’r of (‘an’hn square,     ivhile   t inc ln’vel at vhiicii            t inn’ force     nnis
n’xertn’(I         is innnlin’:ntnnh inn I inn’ 111)1nor ln’ft-hn:n nn(l en rnnn’r. For tecin,iin’:n I rn:isonis           it Prn)V(’nl    ilrrpn)ssii)l(’        to :n(Ijust       t in(’
myth minI I Inn inniti:nl torn                      I ii:tt I Inn’ vnrn’ truly (‘olnnt)arai)l(.

sitting                       that
                  mnn(Imn’atn’s                               (Inn’ nn)nn(’ennt’nttiotiof
                                                                              t                                                              f’on’e              fn’onnn tine i)t’itCe                                 is usually                   located             ntt.       or
nnear       t lie t     il( )n’a(’(      )l in nsl      nit        j in nmnt iotn               ,     rnhn(’in             t   00           inigh         t o i rnnioi)ilizc                             tine            lover        lumi)ar                 segments.
I nn fact.,         inn nn i )n )StL(’t’tll                flexi     ne n \nis                       :t(’t.lnnLi       lv           greater                  i nn some                        subje(’t             s      n’inenn       a     long            i)ra(’e          \\.,5

              than            svmthout                 it.

            N on ne       (   )l tint’       i )t’i(’(’S           t (‘St   (‘(       I (1i( 1 run                 )t’(’       t liar          n linnit-            i nnterspaec                             flexion         n . Actual               i mmoi)iliza-
t   in)ti   I n(’ven’     on’cun’r’(’d                     I nn t inc st aruli                         rig     posit                ion            some            (ainse(1                    inrterspace                       flexiorr       ,    ot hers            Ititer-

SI)nn (‘e ext en i Si n )n i                 I n’r’’sen            ‘ti \(             n)f tIn i s            , Sn )flid                     anou          r it       )f flexionn                    i t i \‘ariai)IV                  a’oflipannie(l                           for-
                                                                                                                                                                          run-:       Jn )URNAI.                 n )l’     boNn:       ANI)         Jn)INl’       S1R(ERY
                                                                           r MMOBILIZING                              EFFD’r          ENCY             OF      BACK                BIt.(’ES                                                                 137

 “ataI                l)eni(Iirng.                 I’ii(.’ eliect                     of      most            braces              ‘as            to reduce                     the arc of mot.iotn                                inn flexioti.                Inn
se’er’al                 instances,                     tine arc                    of motions                    was          shifted             toward                    the extension    side                               of nneintral.                 Inn
these                studies              rio       support                    has          shonvrn            clearly                consistent                   effects              on all subjects.
                hi       the        same                snnI)jcct-s                 opposite                effects              were            rnoted            at        adjacent                interspaces                     with            extenn-
50)1)           Itt      t he         fifth             lumi)ar                 interspace                        arid         fiexioni           at        the         fourth                lumbar                  interspace                   or      ‘iee
 v(’rsa.               No        explanation                             for        this        peculiar                 behavior                  ‘as         found.
                 lire         effectiveness                           of       the         supports                   ivith       respect                to immobilizatiorn                                    seemed               to be related

                                                                                                     FOPWAR.D                                            EEND
                                                                                              COP3ET                                       V5.              BPACE
                                                                                                                  I       MODEL
                                                                                                           X-RAY                               STUDY
            MOD[LT                                                   b-Si                                                                 L4-5                                                                 L3-4
                                                 5TANDNG                              NDING                               STANDING                          [NDING                                 STANDING                      btNDING

                                                                                                   A#{149}                                                              il#{149}

                                                                                                           ‘                          L
                                                                                                                                                                        )‘30                               .

                                                 432101234                                 2IOi23’45                      32IO$’2’YC                              Oi2345                           2$OI24                           OtZ345C
            NOSUPPORT                                                                          iIij        J                                                      _T::_.T_.

           ______                                  4-          .    -p                4-I
                                                                                                     -9’                 4-.
                                                                                                                                  .       -4             4-.

                                                                                                                                                                        -p                    4-
                                                                                                                                                                                                       .       -p             4-.          -i

                                                                                                                                 0 3TANDINC,
                                                                                                                          4-       EXTENSION
                                                                                                                                 ELEXION   -4
                                                                                                                                Fne. 3()
             Effect       of the corset            annd the exl)eninlenrtal                  i)nace      on a patient,           convalescing            froni     ann atta(’k        of low-
         back       pain     and sciatica,             during standing,                 and inn 30 degrees of forward                          bending         (see legend          for Fig.
         2:3). Inn the standing                  position            the brace        caused        appreciable          extension          at the fifth lumbar                interspace
         arnd slight         flexion at the two interspaees                           abov(’, whrle the (‘orset pro(1u(’ed slight- flexionn at. tire lumbo-
         sacral      nini(l fourth          Iunnbar         initerspac(’s        but- slight          externsiorn     nit tin(’ top articulation.                   At :30 (k’grees             of
         forward         iX’In(Iilig,      tin(’ I)race         allowed       sonic      flexion       nit the fifth luniban             inntenspace         h)ut this on’curred              onn
         the extn’nsion            sinin’ of nn’utrah.             At tine nirti(Ultitiotis            nlI)Ov(’, flexiorn       equnih to on nn (‘Xc(’Ss of tirnit occurring
         wit-inout       ann\’ support           V95      rt’eor(le(I.      \Vitin tine cons’t,             on tire other         inaln(1, nit the fifth lunibnir innt(’rspace
         iniotioni      nas     sinnrrl)hv      linnited,         iflIt- it oc(’trrr(’d        on the flexioni          side of n(’utral.             At- the joints         niixve       this.
         nnnotionn roughly              conniparai)Ic            to tinat ocnurninng             with       the i)ra(’e              inotetl     although         witiniin     a different
                 Inn tins          case         ln(’ith(’r           supl)ort               sigiiificanntI’               affected         tire two upxr                            innterspaees.                   At- the      lunibosacnal
         joint     t Inc i)ran’e     niainn tainl(’(I     ann (‘xt4’nded       position                                               without        complete                       innnioi)ilization                    while       th(        corset
         rn’nlueed      t ii(’ lunnrhosannal          anngle  anntl (‘ffectrvely                                                limited       niotion.

niore                to the           discomfort                           produced                        than          to the                magnnitude                     of force                developed                     between                 the
apparatus                         arrd          tine       i)ack.               Inn rronre                 of the              supports                tested                did       the          force            produced                   over        the
paraspirral                     mus(’ies     approa(’in                                     ann uncomfortable                               degree                     during     the early    phases                                  of forward
bending.                     The    (urrennt     practice                                     of employing                            paraspinnal                       upright-s    to immobilize                                    the lumbo-
sacral                spine           ivould               seem                to     i)e       incorrect                  for        two         reasons:                    the       force              is riot        localized                  at     the
points                 desired                arid             does            riot          produce                   the nrecessary       discomfort                                             to cause     immobilizatiorn.
‘Fine action                       of a lov-back      brace                                       should                be to remind        the vearer                                             promptly      that     he should
limit  spinal                       motion    i)y muscular                                         action.                It seems    highly     unrlikely                                           that   any devi(’e       applied
to the                exterior                of the                i)ody             can        effectively                     splint           the          lumbosacral                          region.
            Wit-h                these          corrsiderat-ionrs                             ins mind,                  a brace     is presented,                                   which,            so far as we                        have           beenr
al)le           to      ascertain,                      embodies                       a principle                       not   tried    previously.                                    By          replacing                  the      paraspinnal
uprights                    with          lateral                  uprights                   which               extend              downward                          to the           greater                    trochanters                   arid       by
applying                      force           to         the          lumbosacral                             region             by            means              of       a single                 crossbar,                 two           goals           are
achieved.                        First,             the            force             is kept               localized                  over          bony                prominnenrces                          so      that         prompt                 arid

Vol.       39-A.            No      1. JANI’ARY                     1957
I 38                                                                                          P.         L.        NORTON                      .-ND         THORNTON                         BROWN

soninesvinat-                           in t ironinfn             )rtai)le                  l)ressnnre                    a(’(’ompanries                            fornvard                 bending                      or        siumpi               tig     inn t lie          sitting

position.                         Se(’onn(l,                     a low               pn)mnnt of attachment                                                     for the      lo’er     straps                                         of the              ini)(ionninnai                    pa(1
gi\.(’s             gooni                 (ournter’pr(’ssun’(’                           at. tine lower    (‘till                                            of the    i)raee     without                                           impeding                     sitting             inn the
(‘t’P(’t            posit                ion.            I rln’i(Ieritally,                              side            i)enndirng                   is        t1tnit-e      elTeetively                          l)lockc(1                   by          tine        lateral                up-
               ‘Fine l)er’fonnnnni(’e                                           of t        his          i)raee            ilas          i)eeni            superior’                inn restricting                            flexioni             of         the     lower             lum-
i)ar initerspa(’es                                        inn the               sitting                  position.                      I)uririg                  st-anrdinng                arid          forward                     i)enidinrg                 its effect                  has
l)eenn variai)le.                                        \Vhile                 usually                   effective                       at         the         fourth              lumbar                    interspace,                          its          actions            at        the
lumbosacral                                     jOint            has            i)eeti              to         shift             the           arc         of      motions                  toward                  extensions                      rather’                than           sub-
starntially                             to        t’e(Il.I(’e            ilnten’spa(’e           flexionn.                                    Inn its             brief     (‘litnidal    trial,                               the performance                                      of the
experimental                                      i)race            has           l)(’(’nn ens(’oinraginrg.                                      The              prirnciples        gover’rninrg                                its designs appear                                   to be
solnnr(1           alt hnough furt hen’ n’efimnemenits
                    ,                                      may    be inicated.
               On the i)asis of th(’s(’ studies     it is suggested      that back                                                                                                             supports     could  ivell be prescr’ibed
arnd           probably      fitted nvitln more    ae(’un’acy     if (‘onisiderationi                                                                                                             is givers   to the action     desired.
Certainly                               after’             linmi)osa(’ral                             fusion,                      parti(’ularly                       if a locking    type  of graft                                                              is used,    the
postoperative                                       i)race               should                     produce                       a positions                       of extension    of the involved                                                              region     of the
spine.                  Inn the                  (‘ase           of a lon’doti(’                              spine            with             postural                    backache                     the            opposite                 effect               is desirai)le.
Furthermore,                                        it     is      our     impressions                                    that            inn the                treatment                     of low-back                               pains            a careful                   study
of tine                  history                         will       oft-err reveal                                  whether                       flexions             or extenisiorn                             seems                to      he          the         more              com-
fortable                     position.                          This             i)emnig the                        case,          prescript-ion                            of a suitai)le                          back              sinpport                   should              nrot i)e
j)ur’ely            empirical.
               Sinn(’e the                           ef’fe(t             of a i)n’a(’e                             is trot-            always                   predi(’table,                        it would                        seem      advisable                            to test
tine         (‘ffe(’t                   of tue              i)race               orn(’e              fitted               by           suital)le                  standing                   arid       bending                         roerrtgenograms.
               This                     n’ogn’ess                   report                   ilas       orTnly scratched       the surface                                                          of      the           proi)lem                    of         movement                        of
the           lumi)ar                           sl)inre           arid            honv               to modify        it. Further      study                                                         with    improved                                     techniques                       arid
marnv                   more                    stnI)je(’ts,                    i)otin              those     with     arid  those   without                                                            back    symptoms,                                       would                    seem

             NoTE:                  ‘l’iin’       autinors              wish             to express                    thi(’ir     appreciation                        to     Dr.      .Josepii            S. l3arr, John  Ball                                and      Bucknninsten
 Brownn                 Professor                    of ()rthopaedin’                               Surgery,                 Harvard                  Medical                School           arid         Chief of Orthopaedic                                   $envice    of the
Massa(’hunM’tts       Genwral    Hospital,      for his genneral         supervision       of this    inrvestigationn.      They                                                                                                                         also wish to thank
Robert      L. Hannscnr, Phi).,       Asson’innte Profcssor         of Civil Engineering             at the Massa(’husetts                                                                                                                                 Innstitut4     of Tech-
nrologv,   V. (:‘. Lou, Phn.1),,    forninerly     of tirat   depart-meint,          and    Eugene       Murphy,       Ph.!).,   Chief of Prosthetics
anti S(’nsorv     Aids 1)ivisionn of tinn’ \‘eterninns      Adnininnistration,         for their   helpful      advice  on nianny of the enngineering
l)roi)lenss     whi(’h w(’re enn(’ounnter(’(I.
       Tine t(’(iinii(’al     ntssistanin’(’     of .Jn)inn                                                    \I(’lig(’     :111(1 Thoinias      Brotlerick,     Jr., NI.D.,     nund of the i)nace ninakers                                                                                 Fnirl
l3uschenfc      kit ninni \\‘ilhiainn        t1 urpiny      is                                                   also gratefully           nicknowletlgt’d.
        \Iarv    Cniinouet       was of gre:it         hn(’ll)                                                   inn tire l)r(’Pntrationn        of the mannuscnipt.         I)onnald   W’ithee,  photogra)her                                                                                      at
t lie ‘llassnnchnuset      I 5 ( enn’ral       Ilospit    al                                                      n’ooperated        inn the Prel)nir:it      ion of tine ihlust rat ionns.


 I   .   Tin a           AMERn(.                    N       A(’.       l)l’it               n n1     ( )nn’rnnn 0 l’AEI)t(                      $URGEoNs:                      ( )n’t inol)niedic                   Appliances                      .&t Inns.           Vol.          I . Annnn
          Arbor,             J.         \\.       Idwar(Is,                     1952.
2.        Ixsntx,                 \‘.       T. : S.n1NnoRs,        .1. 13. 1 )EC.       \l.   ann(l ABBoTT,      L. C. : ( )bservationis        On tint’ Funn(’tion of the
          Shoulder                      Joinnt  . J.   Bonne anti Joinnt       Strrg.,  26 : 1-30,   Jann. 1944.
:3.      JnOROAN,                       11. 1-1. : ( )rtinopedic    AI)l)hintni(’(’S.  New    York,    Oxford    University     Press,    l939.
4.        KEEGAN,                        .1. .1. : Alten’nnt iolns of tine Linrnnbar         Curve     Related    to Post-tire     nini(i Seating.     J. Bone anal Joiint
          Stnrg.,           35-A                : 589-603,               Jtnl               1953.
5.        Tnxz,             S. S. : \Iot                     ioni       of       t Inn’ l.uinrbar                        Spinne.              A Ioenntg(’lnoIogi(’                          Study.             Ann.            J.      Ioentgenol.,                     69 : 399-412,

                                                                                                                                         I )ISCUSSI(                    )N

              I )a.         P;un.               C. \Vtn.n.n.-ins,                       I                          ‘faxes:               I )n’. Norton                 arid         1 )n’. Brown                  are     to         be (.4)Iniplinnn(!nnt(’(I                 Oh        tinnier-
takiing             this          (‘onnnl)l(’x              Plohln’lnn.              As            vet        no    h)na(’(’           inas     been         tlesignied             tisat      will function                         with      the             same     effectiveness
Oh        nill inidivitluals.                            Tint’      vn’ny          loosn’-joinnted                        Petn                 annd        tint’ very          firni-joinited                                        ni(5’(i    tVn’()   elitil’(’ly differennt
                    of (‘(ttniPnii’nnt                       for ilnilnnn)I)ihizat join                             of     t inc lower                spinne.          The      use         of the Fnirs(’hnn(’r-wire                                ninarken s was quite       a
novel             i(ieni.          I          olin itn(’hinn(’d           to       h)(’hin’vn’ t hn:nt t in(’r(’ nnnight                                    have        ix’enn a ain                     factor           which             could          inave        alteretl           fume-
tiomn, having                                        fInn’fact thn:nt we
                                          inn nnninnnl                                                                 voluntarily                    splinit t)irr lonver i)nicks inn the                                             Pn’(’snn(’(’ o                 l)ain. Tine               up-

                                                                                                                                                                                     THI       JOURNAL                     OF         HONE          ANI)          JOINT            St’R(’)’RY
                                                                                                      IMMOBILIZING                                            EFFICIENCY                                      OF          BACK                  BRACES                                                                                                  139

pan:ntnns                  t15(’ni               inn (leten’mnnitninng                                  l)r(’sslrr’(                 vnis              of such                  i)trlk           that                it (‘olrltl                have              altered                  tine effectiveness                                     of the
i)rac(’s              sunnt’winat,                                as nvell                 as         the           nnnoi)ihitv                  of the              subjects.
              Tint’             l)rn)h)l(’ni                     of extn’rnal                            flxnttionn                 of tine                lower             spine,               as          I sa’             it,     is that                 of tryinng                  to         immobilize                         a flexible
skelet:nl                  rod          vini(’in                  is atta(’h(’(I                            it (‘a(’h eni(1 to a skeletal                                             ninng:              mnann(’ly,                   the       thorax                 and          the         pelvis.               It     is reasonable
(no        believe                t hat            ,     inn or(I(’r                    tt) a((N)1iil)lisin                           tinis,             a h)race                 nnust           have               (‘nn(’irclinng                   bninnds             which                  provitle               a good                  grip          on
h)n)t in n’inrgs                   aln(I               wininh                   nine      tin(’nn join(’(l                         i)y r’igi(I                i)ars.            Inn my             opinniomn,                     these             l)rinnciples                    have               I)een         best           carried               out
iii        t hnn’ Steininilen’                            i)1ace,                           t mere are ot-in(’r iniodels
                                                                                   alt Inougin                                     (l(’velolx’(I  along tin(’ same lint’s which      hnive been    just
about                 as         (‘ff(’n’tiVt’.                         Tine   Prinn(’il)nil (‘riti(’isnn        I hntve of the t’Xl)en’imenital        1)rnrce is that it- fnsils to take      a firni
(‘mnonngin grip                             on           the           p(’lvis   to I)r(’’(’mnt its posterior           rotation.        The level of the lower horizontal        bannd is too high
to       pr(’vn’nnt                ext(’nnsiomn                          of the htrnsbosnicral         5J)IIi(’.   It is locat(’(l      sligintly below  the axis of ninnto’roposterior    flexionn of
t Ii(’ lnnnnnhan’ 51)ilin’.                                      In the                  ntv(’rag(’                  P(’rsonn           tins              axis         of rotation                            is located                       at      nrbonrt                the          fourth                  lunibnir               vertebra,
niln(I        tii(’ lower                         tramrsv(’n’s(’                         i)In.Ii(l of the                     (‘xp(’rimt’nntnil                             i)rnic(’           r(’sts           just            over          the        spinous                    l)ro(’t’ss               of tin(’ fifth                     luninban’
vert(’h)ra.                      I slrgg(’st                            that             a third                    tranrsvt’rse                        i)amnd            be a(ided                      nit the                level           of the                 sacroco(’(’ygentl                              jmnrn(’tionr.
                  I vanit               to             thank                    I)r.       Nortoin                    and           I )r.          Brownn                 for       forwarding                             their             lntIer              to      me         early              enough                so that                   I had
t innn(’ to                nnnake                  ttp a. nno(iel                              of tire                 h)ra(’e          ann(I             try        it      out.           I found                       it     (1liit-t’          tff(’(’tive  inn pr(’ventinng                                            flexionn                of tint’
lunnhosacral                                 5t)iti(’                  ali(l,            (‘omnt-rary                    to         my             l)rn’(’onn(’(’iv(’(I                      i(Iea              fronn                  readinng            the I)nll)(’r, it was                                        far          more               com-
fortable                    thrum                I hatl exl)en’ted                                      it iottld                    I)e.         All         these             criticisms                       are           intended                     to be             connstrtrctive,                          and            I sincerely
hnot)n’ t hat                     t Inn’ authors                                   will         (‘onitilnun’                   with                this           investigation.                               They                   will      have              t’ontril)trte(I                          a greiit-               deal          if they
(#{149}fl    n’i(I ins of the                                manrv                     nn(’ffe(’tive                       i)rntces              wini(’ir             I am inclined                                  to speak                    of as ‘‘ntnisannce                                   ‘‘   i)ra(’es.           Such                  braces
I )llsii t hi(’ JELt i(’lit in inn ona’ pl:n(’n’ ann(l l)lrsin                                                                                    mimi out. in annot hen’, i)lnt. t heir’ onnly effect                                                                              ivo’nn’ss               I in’s inn t-in(’ fact                      t hat
t Inc J)ntt i(’nit (‘V(’nit tDnll\  giv(’s  l1J) :01(1 (lt’(i(h(’s                                                                                   t 0 iiOl(l still.

                  1 )nt. ln             (    ;   EN E \l                  1     lUll       l’Y,          N                   in )RK          ,     N. ‘n’.: It is a I)l(’zistrr(’                                         t o (his(’tnss                t-inis         stinntnlat                1mg l)nip(’r.                      1(’hnah)iIitni-
t in)nn       nil      ni 1)it i(’lnt                       nit          in a 51)111111 annonnalv                                       r(’(iinin’es                 a brace                   that             will           provide                 the            necessary                       immobilization                                 of the
innVOlVn’(i                     laint              V(’t           I)(’lIiiit                nninixinnnnnnnn funnctionn                                          of the              remainder                             of tine              body,              so that-                  the            back         will              Ix’ free            to
nnnov(’             OV(’l’          as gn’eat-                           a lenigt               In as               possible.                The               niuthors                show                   that             some            h)races                 practi(’ally                        r(’v(’rse               tine        proc’ss,
t(’nn(linng                to      st-rinng(’ntlv                                 hinnnit             gross            ton’so           niovenuemnt                          vet          riot          adeqiratelv                           imnnobihizing                               tine         innvolv(’(l                 segments                    of
I Inn’ sinie.                     A         nnonnninnl                    stni)j(’ct              ,    lnliinniiii)it(’(I                        iiy       l)1i1i,          ‘VaS          ai)le           to         nnov’              the         crit icnil vertebrae                                    inn hx’nnding                      forvard
:ngainnst                  t Inn’ 1rac’                            e%’(’li              nnnon’e t ham                        Ii(’ tlini                 1)enrdinng                for’vnird                    it         hnonnt. a bn’ni(’e ; t his                                  v:is             l)ossii)he              i)ecause                   t   inn’
I )l’’55)1           l’n’ of          t inn’ h)n’nt(’(’ (‘X(’n’t(’(l                                    a fon’ce                of      it       s oivnn.
              ‘Fiiis             :nnnalvsis                       of          nn:nniv           tvp(’s                of      h)rac(’s,                  lnnid(’n’takn’nn                      sit-in           the            :nini of          Pn’ofessor’                   Flnnnnsenr                   annd       mis         enrginn(’(’ninlg
(‘oll(’agnu’s                      nit t lie                      \Intssa(’hntns(’tts                                 Innst itontn’                     of Tecinniohogy,                                 has           (‘uhminnat(’d                            inn nm inn(’r(’ased                                unntierstanndinng                           of
t hiP ant              ionn of                    t lie          foi’ces                 exen’ted.                    The            pn’(’sstnn’e                  sino(’s           (‘lannI)etl                     to         tine         h)rni(’(’          h)ntrs         ‘ere              rather               (‘luninsy                 i)nrt. t Inc
I )(‘st           nnnn’anns availah)l(’.                                          Tine            (l((t             n’ic:nI st n’ainn gaug(’s                                     Pen’mitt-ed                        a(’(’nnn’at(’                  nnreasun’ennent                              of        forces            tnnnd(’n’ nnenirly
isn)lii(’t           nm’          n’n)ni(Iit                ionns.                Font          inniat              ‘lx’ Ion’           hint in(’r’                    expen’irnt’nrtat                          on            t he          Frau           klinn             Innst itute                    Laix)ratories                             inave
1(’(’(’      nit ly nl(’V(’lol)(’(I                                    fon’ tint’               (inanternisastn’n’                                 (rps                   1i(’V      (‘l(’(’tn’in’al                   n’al)ni(itnin(’(’                        galrg(’s,                 vhich                   nire aIx)lrt                 t he      siz’
of a n’oinn                 ,    to) rnnennsun’o’                             l)n’(’Sstir(’                 h)et iV(’t’nn t hit’ hnorniininn I)O(i\’                                            annd            ann nt(ija(’(’nit                      srrn’fnice              “.     These                  ‘‘    Filpips            ‘   ‘,    as      they
 in(’ n’nnllo’d,                   nine (‘urr(’nnt                               lv beinng                    lrSt’(l         to      ns(’astrn’e                                                betwo’(’ni                     urn ninsl)utat-ionn                            stump                   arid          tine     socket-                 of ann
nort ifin’ial                   hi nrnl i. Tia’v                              should                   l)(’rnnnit.            nion’(’             an’cun’at               e (lo’ternninnat-ionns                                      of t lie sLnI)port                            offen’ed                 h)\’ a I)ra(’(’,                     (‘onset,
ni’st n’ainninig                    st n’:),                   on’ Plnist(’n’                   n’:nst          .    Tine       snnsall                size       of tine                 Filpip               ‘‘ woirld (‘Iiniinnnite tire need for’ slots or n’(’I)Lnil(ling
nof I inn’ aI)I)hiannn’(’                                   annd                omnlo1                (‘a115(’          oniI            nneghigible                        (‘inanigt’             inn t inc pn’essirn’’                              o(’(’un’n’inng                  inn the                absence                 of         a grunge.
              Thin’             n’xI)(’rinnio’nital                                    brace            s(’o’nnis             St)lrnn(1                Irons           ann o’nnginneerinrg                                stnrnndpoirnt                     .    I )ur’ing                irntlcsirnible                       movo’nnt’nnts,
it applies                       t Inc t hnee-poinnt                                       hn’nicinng                  Pninn(’il)l(’                    ; a localized                      ani(l          unn(’onnfon’tah)ho’                               l)resstrn’o’                  is cnius(’(l                inn t lie            n’egionn            of
t inn’ lna                 I :nn’k vinenn’                               it siionnlni                   ix’ nniost.                 effective                      annd         (‘onrniten’pn’(’ssmrn’(’s                                nine (‘x(’rte(l                      h           lonng            leven’       an’nis.                The       tvo
v(’nt        in’ntl I ans                        ann’ t Inin’kest                           fn’onni fn’onnt to) n’(’an’, givinng                                                    nni:ixiflnlinni                    stn’(’nigt              In and                 st iffnu’ss             inn t he               Plane            smnbject                 to)
gno’at est                  1a’nnolinng                          lnatnls.               The            lon’est                st nap               is s’,ViV(’ll(’(l                      so      t hat              it- is s(rh)st annt iallv                                 in linne wit in t he annatonnical
axis,             nnninl I Inn’ st-l’nil)                               follovs                 inn a niat-un’al                        fold              of thin’ hotly                         dinrinig                 sitting.
              ‘Flit’            annt lions                     snnggest                   t hint nlisn’onlfort                                   fronn            a I)rao’e               selves                as a reminnder                                  to t lie pat iennt                          to      hrnice            ininiself               l’
I )11 II inng              I )an’k               t 0) i      n’o)rn’o’o’t- (annti                               connrfon’t  nih)lo’) 1xsit                                  ionn ivith                    his ovnn ninnnscles,                                        nviiicin are inntact                              inn t hera’ cases.
Pn’rin:nps                      I inn’ ext               rennno’ inn sinn)lio’ity                                      of brnu’e    designi                                     vould               be          m’rely                   a corset                     steel          amid          a thumb                     tack!
              Thin’ st nikinig                                   van’iat                lOInS          i)(’tWO’eni                 i)n’ac(’s               nini(I thin’ differences                                        betwet’nn                  inndividunils                         suggest                   furtiner                  adnipta-
I in)nn ton I his                           fin’lnI         n)f t ha’ pn’(’s(’n’ipt                                  ionn      tn’ann                  ivinicin           has        been                so      effective                     inn solvinng                       other               prost.hn’t-ic                  and             on’tIio-
pan’nhin’ :npphi:nnnn’(’                                     prn)I)lennis                              Thin’ don’tor,                            tEn’ bran’n’                   fitter,           the            t-h(’rnrpist,                      plors        ninny other                      necessary                    n’n)nrsultannts,
cann sn’ln’n’t ninini later                                              n’vahnatn’                     t lie         pant         icmilan’              :ip)liannn’n’                 login’ally                     nnn’enIn’nl Ion’                      t inn’ innnlividual                             l)nit iennt        .     This             l)nIlx’n’
shnoonlol              si ininnnlutn’                        thin’ t hiinikinng                             of t Inn’ emit inn’ I n’:tnn.
              :      I’nt.NK,                      \\.            E.,             :nnnnl (             nnsoN,                 H, .J. : A New                                      Pr(’ssur(’-Sn’nisinig                                      Innstrurnnn’nnt.                       .J.     Frannkhinn                  lnnstitirto’,                   238:
21           30.       195-I.
                  I. I3n.nnnnnr.,                            (    ‘.      0. :           ‘[Inn’         !rost               hint in’s             (‘hinnic             ‘I’n’:inni.             Artifin’ial                       1innnhs,                I : 9- 1 -1, 1954.

                  I )it.        l3nnn        v          N      (n’losinng                 ) : I sinonnlol                     hikn’ tO t hnanik                             thin’ niiscussors                              Ion’ t inn’ir               t-inougintftnl                       (‘ritin’isnnis.                  I )r.         Wilhianns
in:ns ininntn’nl                            onit            nIef’ncin’nnn’ies                           inn 0mm’ tn’n’iinniques                                      of      ivhin’h               nyc          nire           i’el1          nian’e.                 I thinnk               an’              (lisn’trssor                 nvho           ivill
                                                                                                                                                       ( (7o,nli,n          nI((1     09          page               220)

VOL               39-A,           NO). I, JANUARY                                              1957
220                                                                                                                                   (;.     \v,         N,      EGG            ERS

                                                                    i’no.              3-.                                                                                                                                    Fro.             :3-13
             Fig.              :3-     : l1oositioono vtno’nn                                      oson                moot            on tine ioeo’l.
             l’ig.             :3-13 : I no’ssoon                     oonn I           mo.      Ito   ni     sloo onvinog I io:ot t ho’                        ilnnti       pni’V(’nit          s    t tie     stIll!’       an’t’no         fnonnn      t o)000’tninng I mo’ stout’

i)\’ a bursitis                                 I)(’t     \\((,fl                t lie          1115(111            arid          t    he (‘al(’anleal                            spun’.             ‘[CI      I’(’lie\’e                j)1’(’ssUl’t’            (Iii        t    lit’ painful
nLr’(’a.           \\‘(‘          lnnnv(’          too’         ‘ean’s                       n’(’o’onssnnit’nn(l(’(l                          to      (lion’            patienits                    a      t’orsinsa-shntped                                 sli(Ie              1111(1      \vini(’li
has             lu’(’ni              l()unntl             v(’n’v                 oat         i’I’aet on’s’. l’lne                             use          of           tisis          device                Isas         for’           rnanny           year’s                  (‘linssiniated
I lit’ noet’d                        for’       sun’g(’r’v                   inn t Inese                       l)totit’not             s.     Sligist-              a(ijust-nsenits                              Issay            he           nnecessar’y                    inn on’d(’n’               to
nd      i(’Vt’             t   lit’ pn’t’stn ne                        (    In         t I nt         spin n’.
                Flie              rn(’(’llanni(’al                           l)r’in(’il)l(’ tise
                                                                                         of                                           itd   is to relieve       pressure                                                  arid            to        lesseni            strain                on        t-h(
init’tlial                 asl)’’t                 (If       t lie           eah’nonneus                            ‘hcn’e               the medial       plant-ar       fascia                                                   is innserted                         into            the         ar’ea
(If     tis(’        5MI’.                  Tine         slinix’                   arid             (‘Grist         n’u(’tionn                of tise pad                           does            this.           It must                    i)e of suth(’iennt                             height
to         pn’(’\’(’nit                                                     (Inn         t lit’            spun’,          arid              althoingli                         the        l)ad             may            be            made             of any                     mat(’r’ial,
\\‘e        have                 ftnnnid                that               sponge                          rubber’,              one-half                        inch                 thick,             is the              niost              satisfacton’y.


                                                                                                   lnnnnoBrLnznNG                           EFFICIENCY                       OF        BACK              BRACES

                                                                                                                      (Continued                     from               page          1.311)

tnoko’ t lie t innio’ t 0)                      nnnnoke         no     ‘opy                  of t toe tlrnoo’(’            1011(1 toy               it- out,            (‘ertloinily            desen’ves                to be coniplimenot-ed.                                    I sinould           like
to     o’onnnnennt                    ono omit’          1)(Iinot           tinat            lie      nnnadt        inn lxorti(’tnlnor.                    He l)ostulnnted                           that        nomn’ hrnoce, to insmoi)ilize                                       this      norea       of
tln(       i)IOt’k t’fTo’o’tivo’lv,                         nnust                gri’l        loootio tht’            l)(’lvis              nonid the           tinorax.                If this           were           possible,               I would               agree.           However,
it wnos our                     fino(hnog          t-inat           onto t)rao’o,                     n’(’gan’dlt’ss         of the                type         of l)t’lvic              atta(’innns(’mnt-                used,            actonnolly           did       grip          the       pelvis
(‘fI’O’(’t.iVelV.                 l5inis         vnos        tioc          ro’nosuno               t bat       we      at)ntnn(i(Imnctl                   noll braces                  designn(’d             to)    grij)        the          p(’lvis        annol rtsorto’(l                    to    tine

Pn’o’so’nnt. ioo:oee nvioio’to gives no loono Jloinit                                                               ((t fix:ot ioonn nonntl lolenolizes                                 pn’(’sstrn’t’          nos nne8n’ t lot’ JIo)init                       vioo’n’e            ininninootoilizno-
t iono is oh’sineol os J)(ossitOl(’,

                                                                                                                                                                                         ,n.onf: Jo)URNA0.                       0)1.’     nooxi;        ANO)          Jo)nNn’           sooto;n-;nv

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