Screening for Psychological Factors in Patients With Low Back by liaoqinmei

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									                      Screening for Psychological Factors in
                      Patients With Low Back Problems:
                      Waddell's Nonorganic Signs
                                               or the majority of patients with low back pain (LBP), the cause of their
                                               pain is unknown.' Psychological factors, which may include behav-
                                               ioral, cognitive, or somatoform components, can be just as important
                                               as the diagnosis of pathology affecting the low back in a patient's
                                       recovery from a low back p r ~ b l e r n . ~ - ~
                                                                                  A recent US Agency for Health Care
                                       Policy and Research clinical practice guideline recommends exploration of
                                       psychological factors when an individual with an acute low back problem is
                                       having difficulty regaining his or her tolerance to a~tivity.~

                                       Feuerstein and Beattie5 discussed several biobehavioral instruments that can
                                       be used to identify psychological factors in individuals with LBP. If factors are
                                       identified that are potential contributors to the low back problem, the
                                       physical therapist can then refer the patient to the appropriate professional.
                                       Routine application of these instruments, however, may be impractical during
                                       physical therapy examinations because of the time required for administra-
                                       tion and scoring as well as the expertise needed to interpret the results. Thus,
                                       there is a need for a brief screening tool to help identify patients who may
                                       require more detailed psychological testing. A review of the description and
                                       diagnosis of psychological disorders that may relate to LBP is beyond the
                                       scope of this update. For further information on these areas, the reader is
                                       referred
                                       Signs of organic problems are findings from the physical examination that
                                       indicate the presence of pathology or disease. Paresthesia over the lateral
                                       border of the foot, for example, is a sign for S1 nerve root involvement. Signs
                                       of nonorganic problems, in contrast, are findings that deviate from the usual
                                       presentation of d i s e a ~ eBoth organic and nonorganic signs may be present
                                                                    .~
                                       in a patient with LBP. Therefore, the presence of nonorganic signs should not
                                       be equated with malingering or the presence of a psychological problem, but
                                       only with the need for further investigation.

Scalzitti DA. Screening for psychological factors in patients with low back problems: Waddell's nonorganic signs. Phys
Thm. 1997;77:306-312.1

Key Words: Assessment, Low back problems, Nonorganic signs, Psychosocial.




David A Scalzitti

306                                                                    Physical Therapy. Volume 77 . Number 3 . March 1997
                                                                           The presence of
                                                                           nonorganic signs
Waddell et aI8 described a group of signs that indicate                    should alert the                        nation is scored as posi-
the presence of nonorganic problems for patients with                                                              tive. If a sign is positive,
LBP. Waddell has also referred to these signs as "behav-                   clinician to the                        then that type of non-
ioral signs" or "inappropriate ~igns."2.~Testing for these                                                         organic sign is present.
signs is performed as part of the physical examination
                                                                           need for more
                                                                                                                   One nonorganic sign in
and takes less than 1 r n i n ~ t e Nonorganic signs have
                                    .~                                     comprehensive                   isolation may be present
been used to describe different characteristics of                                                         with some organic con-
patients with LBP. The purpose of this update is to                        testing.                        ditions    and    should
describe the use of Waddell's nonorganic signs as a                                                        therefore be discounted.
screening tool for psychological factors in patients with                                                  A sensory regional dis-
LBP. Additionally, the relationship between the non-                       turbance, for example, may be present in persons with
organic signs and physical impairments, disability, and                    spinal stenosis with multiple nerve root involvement.
treatment outcomes will be discussed.
                                                                           Waddell et als found that the presence of three or more
                                                                           types of nonorganic signs correlated with the results of
Waddell's Nonorganic Signs                                                 psychological tests indicating problems. According to
In the early 1900s, nonorganic signs were frequently                       Waddell et al, the presence of a single sign is not
used to detect malingering in patients with LBP.lOJ1       As              associated with an indication of psychological problems.
medical and psychological knowledge progressed, it                         The presence of three or more types of nonorganic signs
became clear that the diagnosis of malingering may have                    has been the most consistently used criterion for the
been based on overly simplistic assumptions, and the use                   finding of a positive Waddell's nonorganic signs test,
of these nonorganic signs fell out of favor. The modern                    although other methods have been proposed.12J3 Unless
use of nonorganic signs for patients with low back                         otherwise specified in this update, therefore, a positive
problems increased greatly after 1980, when Waddell et                     test for nonorganic signs refers to finding the presence
a18 grouped eight signs into five types. These five types,                 of three or more types of nonorganic signs. A negative
or categories of signs, are tenderness, simulation, distrac-               nonorganic signs test is the finding of only one or two
tion, regional disturbances, and overreaction (Table).                     types of signs, although a patient may have more than
Waddell and colleagues investigated 16 other signs,                        three nonorganic signs because of multiple signs within
including grip strength, lumbar sensory changes, and                       a specific type.
pretibial tenderness, but did not include them in their
final battery because of poor intertester and intratester                  Reliability
reliability, overlap with other signs, and difficulty for the              Agreement was high (86%) for two examiners in detect-
examiner to learn.                                                         ing the presence of nonorganic signs in a group of 50
                                                                           patients with chronic LBP.s Agreement between exami-
According to Waddell et al,s a nonorganic sign (an                         nations in the same patients was 85%. (The mean length
indication of a nonorganic contribution to a patient's                     of time between examinations was 23 days.) McCombe et
low back problem) observed during the physical exami-                      all4 reported poor intertester reliability between two



DA Scalzitti, PT, OCS, is Clinical Instructor, Department of Physical Therapy, University of Illinois at Chicago, 1919 W Taylor St (M/C 898),
Chicago, IL. 60612-7251 (USA) (david.scalzitti@uic.edu),and Specialist in Physical Therapy, Department of Physical Therapy, University of Illinois
Hospital, Chicago, IL 60612-7233. Address all correspondence to Mr Scalzitti at the first address.

Physical Therapy . Volume 77 . Number 3 . March 1997                                                                               Scalzitti   . 307
Table.
Waddell's Nonorganic Signsa


 Type of
 Nonorganic Sign              Nonorganic Sign            Description

 Tenderness                                              Tenderness not related to a particular skeletal or neuromuscular structure; may be either
                                                           superficial or nonanatomic.
                               Superficial               The skin in the lumbar region is tender to light pinch over a wide area not associated
                                                           with the distribution of a posterior primary ramus.
                               Nonanatornic              Deep tenderness, which is not localized to one structure, is felt over a wide area and
                                                          often extends to the thoracic spine, sacrum, or pelvis.
 Simulation tests                                        These tests give the patient the impression that a particular examination is being carried
                                                           out when in fact it is not.
                               Axial loading             Low back pain is reported when the examiner presses down on the top of the patient's
                                                           head; neck pain is common and should not be considered indicative of a nonorganic
                                                           sign.
                               Rotation                  Back pain is reported when the shoulders and pelvis are passively rotated in the same
                                                           plane as the patient stands relaxed with the feet together; in the presence of root
                                                           irritation, leg pain may be produced and should not be considered indicative of a
                                                           nonorganic sign.
 Distraction tests                                       A positive physical finding is demonstrated in the routine manner, and this finding is then
                                                           checked while the patient's attention is distracted; a nonorganic component may be
                                                           present if the finding disappears when the patient is distracted.
                               Straight leg raising      The examiner lifts the patient's foot as when testing the plantar reflex in the sitting
                                                           position; a nonorganic component may be present if the leg is lifted higher than when
                                                           tested in the supine position.
  Regional disturbances                                  Dysfunction (eg, sensory, motor) involving a widespread region of body parts in a
                                                          manner that cannot be explained based on anatomy; care must be taken to distinguish
                                                          from multiple nerve root involvement.
                               Weakness                  Demonstrated on testing by a partial cogwheel "giving way" of many muscle groups that
                                                          cannot be explained on a localized neurologic basis.
                               Sensory                   Include diminished sensation to light touch, pinprick or other neurologic tests fitting a
                                                           "stocking" rather than a dermatomal pattern.
  Overreaction                                           May take the form of disproportionate verbalization, facial expression, muscle tension
                                                          and tremor, collapsing, or sweating; judgments should be made with caution,
                                                          minimizing the examiner's own emotional reaction.

"Adapted from Waddell G, McCulloch J.4, Kurnmrl E, Venner RM. Nonorganic physical signs in low-back pain. Spine. 1980;5:117-125.



orthopedic surgeons and between a surgeon and a                                 Keefe and Block16 described a method for observing
physical therapist in detecting individual nonorganic                           overt pain behaviors to provide a means of identifying
signs. Confidence intervals of Kappa coefficients                               the presence of guarding, bracing, rubbing, grimacing,
included zero for the nonorganic signs of tenderness                            and sighing during a physical examination. Waddell and
and regional disturbances, suggesting that agreement                            Richardsong obtained a Pearson product-moment corre-
was not better than chance. McCombe et al, however,                             lation coefficient of .65 when examining the relationship
did not examine the reliability of the examiners in                             between the nonorganic signs test and overt pain behav-
determining the presence of three or more nonorganic                            iors in 120 patients who had LBP for at least 3 months.
signs. This finding should caution clinicians regarding                         Measurements obtained with the UAB Pain Behavior
the use of positive nonorganic signs in isolation.                              Rating Scale, which is one instrument for measuring
                                                                                pain behavior, were also highly correlated ( r =.73) with
The nonorganic sign of overreaction requires the clini-                         the results of the nonorganic signs test in 103 patients
cian to make judgments based on observations of the                             with LBP.I7
patient's behavior. The other signs are from tests con-
ducted during routine examinations. The presence of                             Nonorganic Signs and Psychological Findings
overreaction, therefore, may be more difficult to identify                      In their original study of nonorganic              signs, Waddell et
than other nonorganic signs. Several methods and                                al-eported     a correlation between               the presence of
instruments can be used to quantify observation of a                            nonorganic signs and scores on the                 hypochondriasis,
patient's behavior during the physical examination.15                           depression, and hysteria scales of the             Minnesota Multi-


308 . Scalzitti                                                                               Physical Therapy . Volume 77 . Number 3     . March 1997
phasic Personality Inventory. These scales of the Minne-                        with LBP who were seeing an orthopedist for the first
sota Multiphasic Personality Inventory traditionally rep-                       time showed three or more nonorganic signs. The
resent a measure of psychological distress in patients                          authors reported three or more nonorganic signs in 33%
with LBP. In addition, correlations have been found                             of two different samples of patients with chronic LBP
between the presence of nonorganic signs and other                              a n d in 50% of a third sample of patients with chronic
psychological instruments, including the disease affirma-                       LBP. The three samples of patients had all been off from
tion and hypochondria1 disturbance scales of the Illness                        work for many months with a high incidence of previ-
Behavior Questionnaire (IBQ),IRthe Distress and Risk                            ously failed treatments. No positive tests were detected
Assessment Method (DR,4M),I9 and pain drawing^.^.^^                             among subjects without LBP. Factors responsible for the
Waddell et alRcaution, however, that nonorganic signs                           increased occurrence of nonorganic findings in patients
should not be overinterpreted and used as substitutes for                       with chronic LBP have not been identified. The likeli-
comprehensive psychological assessment. Instead, they                           hood of finding three or more nonorganic signs may
should be used as part of an examination to identify                            increase with the duration of the problem or because of
patients who require more detailed testing.                                     the failed treatments.

The sensitivity and the specificity of eight psychometric                       Nonorganic Signs and Tests of
instruments, including Waddell's nonorganic signs test,*                        Musculoskeletal Performance
for detecting psychological disturbances in patients with                       Nonorganic contributions to a patient's LBP may coexist
LBP were determined in a group of 264 persons.I2                                with organic contributions. Organic findings may be
Results from each instrument were compared with a                               influenced by nonorganic factors, and in some patients,
"gold standard" of psychological disturbance, which was                         nonorganic findings may be influenced by organic fac-
defined as a positive response to three or more of the                          tors. Waddell et a122 evaluated the relationship between
eight psychometric tests. Specificity of the nonorganic                         the presence of the nonorganic signs and 27 tests of
signs for correctly identifying patients who were non-                          musculoskeletal impairments in 120 patients with
psychologically disturbed was 86% in men and 84% in                             chronic LBP. Reproduction of the patient's pain during
women. Sensitivity of the nonorganic signs for correctly                        hip and knee movements and limitations in passive knee
identifying patients who were psychologically disturbed                         flexion, hip flexion force, hip abduction force, and
was 44% in men and 48% in women. This study                                     prone isometric trunk extension were positive more
was limited, however, by the lack of a universal "gold                          frequently in the patients who had two or more non-
standard" of psychological disturbances with which to                           organic signs (29%) than in the patients who had only
compare the different instruments. In the study,                                one or no nonorganic signs (71%). The only impair-
measurements with each instrument were compared                                 ments not correlated with a nonorganic component
with a compilation of measurements obtained with                                were those related to spinal posture and lumbar flexion.
the other instruments. Correlations among the eight                             Based on these findings, the authors concluded that the
instruments may not have been found if the instruments                          physical tests of musculoskeletal impairments that they
were measuring different aspects of psychological                               investigated were better indicators of illness behavior
disturbances.                                                                   than of physical impairment.

Nonorganic Signs and Demographics                                               Groups of patients with LBP with three or more non-
Age, gender, occupation, or compensation status d o not                         organic signs performed poorer on tests of force pro-
appear to influence the results of the nonorganic signs                         duction, range of motion, and motor skills than did
test.Wayes et al," however, found nonorganic signs                              groups of patients with LBP without nonorganic
more frequently in patients with LBP who were antici-                           signs.2"-'"hese  tests included tests of lumbar range of
pating or receiving financial compensation as compared                          motion and isometric force on an Isostation B-ZOOThf
with those who were not anticipating or receiving com-                          lumbar dynamometert.2"24and tests of lifting, gripping,
pensation. In this study, however, other factors differed                       and physical dexterity o n an ERGOSTMWork Simula-
between the two groups of patients. Thus, the role of the                       tor.x." Menard et a12Vound that patients with LBP with
nonorganic signs is difficult to assess.                                        nonorganic signs produced lower torques for isometric
                                                                                elbow flexion and isometric knee extension than did
The length of time that a patient has had LBP appears to                        patients without nonorganic signs. The authors con-
increase the likelihood of finding a positive nonorganic                        tended that musculoskeletal performance as measured
signs test. Waddell et alQeported that 12% of patients                          by dynamometers does not necessarily reflect maximum
                                                                                physical capacity. Low values on any of these tests,

'The seven othrr instrumenrs \+,err a pain drawing. the Slodified Somatic
Perception Questionnaire. the Hospital Anxiety Scale, the Hospital Depression    Isotechnologies Inc, 328 Elizabeth Brady Rd. PO Box 1239, Hillsborough. NC
Scale, rhr Zung Depression Scale, the Illness Behavior Questionnaire. and a     27278.
nonorganic svmptoms test                                                        'Work Recovery Inc, 2341 S Friebus, Suite 14, Tucson, . 2 85713.
                                                                                                                                       4



Physical Therapy . Volume 77 . Number 3        . March 1997                                                                                 Scalzitti   . 309
however, could not be used to identify individuals with       patient's work status. A poor surgical outcome in this
nonorganic problems, because some individuals with a          study was defined as postsurgical episodes of disabling
positive nonorganic signs test scored as well as some         back or leg pain, chronic use of narcotic medications,
individuals without nonorganic signs.                         further surgery, or inability to return to work. Relief
                                                              from pain and reduced disability depended on the
Cooke et a124 measured force and range of motion in           presence of an accurate diagnosis of a surgically treat-
patients with chronic LBP, using a lumbar dynamome-           able pathological condition without the presence of
ter. The same test was repeated after 4 weeks of an active    nonorganic signs.
reconditioning exercise program. Patients with a positive
nonorganic signs test demonstrated improvements in            Outcomes of nonsurgical treatments of patients with
force that were greater than improvements that might be       LBP have also been influenced by the presence of
expected as a result of physiologic changes or a learning     nonorganic signs. Lehmann et also found that electro-
effect of the test procedure. The authors suggested that      acupuncture treatment of patients with chronic LBP
the improved force generation might have been due to          who had three or more nonorganic signs was no more
alterations in illness behavior rather than to an improve-    effective for pain reduction than a sham treatment. In
ment in physical capacity.                                    contrast, the authors found that treatment of patients
                                                              with electroacupuncture, in the absence of nonorganic
Findings that nonorganic components may contribute to         signs, resulted in a greater decrease in pain than did the
measures of musculoskeletal impairments suggest that          sham treatments.
these measures, which are frequently used by physical
therapists for patients with LBP, may also reflect a          Patients with illness behavior as measured by the pres-
psychological component of disability. In addition, these     ence of nonorganic signs, nonorganic symptoms, and a
data suggest that physical therapists may want to con-        pain drawing received more treatments than did patients
tinue measuring musculoskeletal impairments but need          who did not exhibit illness behavior in a study by
to consider the influence of other factors, such as illness   Waddell et al.31 These treatments included medication
behavior, on these tests. Likewise, benefits from treat-      use, lumbar injections, orthopedic supports, physical
ment focused on physical reconditioning may result in         therapy, spinal manipulation, and bed rest. Based on this
reducing disability by improving an individual's psycho-      finding, a clinician should seriously consider whether
logical status, and thus his or her tolerance to activity,    there is overutilization of treatments when patients who
rather than just improvements in the measurement of           test positive for nonorganic signs show no progress. For
musculoskeletal impairments, such as peak torque of the       these patients, treatment might be directed toward
lumbar extensors.                                             addressing the illness behavior.

Relationship Between Nonorganic Signs and                     Ability of Nonorganic Signs to Predict
Treatment Outcomes                                            Return to Work
Nonorganic phenomena can interact with expected               A common goal in the rehabilitation of workers with
treatment outcomes in patients with LBP. Several inves-       LBP is to return them to work. There is conflicting
tigators"-29 have described poorer results from lumbar        evidence about the ability to use nonorganic signs for
surgery in patients with nonorganic signs. McCull0ch2~        predicting return to work. Bradish et a132reported that a
found that 97 of 109 patients with a nonorganic compe         positive nonorganic signs test at initial assessment in a
nent who underwent chemonucleolysis continued to              group of workers with a low back injury (N= 120) did not
have back or leg pain that prevented their return to full     correlate with work status between 12 and 18 months
activity. One hundred eighty-six of 327 patients without      after injury. In contrast, 0hlund et all7 found a relation-
nonorganic signs, in contrast, were free of pain or had       ship (r=.34) between nonorganic signs and the time
minimal limitations in activity following the chymopa-        needed by a group of automobile workers (N=103) to
pain injection. Dzioba and DoxeyZ8  found that only 49%       return to work. In this study, return to work was defined as
of patients with two or more nonorganic signs were            the return to the same job at least half-time.
approved to return to work by a physician 12 months
after various forms of lumbar surgery, as compared with       Lancourt and K e t t e l h ~ tin~a~study of 134 patients with
                                                                                             ,
78% of patients who had only one or no nonorganic             LBP, found that the nonorganic signs of axial loading,
signs following surgery.                                      simulated rotation, distraction, and a sensory regional
                                                              disturbance were among the factors that were better
In a prospective study by Waddell et al,Z9 psychological      predictors of return to work than were ankle and knee
factors, including the presence of a positive test for        reflexes, motor loss, and sensory loss in a dermatomal
nonorganic signs, correlated with a poor surgical out-        pattern. This relationship was seen for patients who
come, as assessed by a physician, the patient, and the        returned to work within the first 6 months after injury



3 10 . Scalzitti                                                         Physical Therapy   . Volume 77 . Number 3 . March 1997
but not for patients who were off work for greater than        as a malingerer does little to help the patient enhance
6 months. Recently, KummelS4described two new non-             his or her tolerance for activity. Instead, the factors that
organic signs: lumbar pain during isolated cervical move-      are limiting the patient from recovering his or her
ment and lumbar pain limiting active shoulder move-            tolerance for activity should be identified, and interven-
ment. The presence of these two signs in addition to the       tions should be targeted toward modification of the
presence of three or more of Waddell's nonorganic signs        limiting factom5
improved the ability to predict patients who failed to
return to work in this retrospective study of 717 patients.    Classification of movement dysfunction in patients with
                                                               LBP may help clinicians to identify individuals who will
The treatment received by injured workers may influ-           benefit from specific treatments. Failure to account for
ence their return to work. Werneke et all3 evaluated a         the presence of nonorganic findings may lead to the
physical conditioning program designed to meet each            misclassification of patients, because nonorganic factors
patient's job requirement for 170 workers with LBP. One        may influence patients' performance on tests used to
hundred fifteen of the patients showed work status             classify them. Delitto et a135 screen for nonorganic signs
improvement within 3 months of completing the pro-             in their treatment-based classification scheme and sug-
gram. At least one nonorganic sign was present in 47%          gest referral to an appropriate practitioner when screen-
of the patients whose work status did not improve, as          ing is positive. Marras et alS6developed a classification
compared with 12% of the patients who demonstrated             scheme for patients with low back disorders based on the
improvement. The number of nonorganic signs present            higher derivatives of trunk velocity. Using this method,
at discharge from the program was reduced for 82% of           Marras et a1 found that patients with nonorganic find-
the patients whose work status improved. In contrast to        ings were distinguishable from patients in nine other low
the high su.ccess rate from physical conditioning, when        back disorder categories.
patients with nonorganic findings received treatments
described as "symptomatic and at the discretion of the         The utility of Waddell's nonorganic signs has been
physician," less than 40% returned to work.92                  described for patients with LBP. To date, nonorganic
                                                               signs tests for musculoskeletal problems in other regions
 Other factors, besides the presence of nonorganic signs,      of the body are not commonly used. Development of
 may influence an injured worker returning to previous         nonorganic signs tests for patients with other musculo-
job duties. Waddell et alZ9 found return to work after         skeletal problems may help to guide management of
 lumbar surgery was predicted by physical, psychological,      these patients.
 and occupational factors. Physical therapists should con-
 sider the relationship of these factors in the treatment of   Nonorganic signs are found more frequently in persons
 injured workers. The referral to an appropriate profes-       with chronic LBP as compared with persons with acute
 sional or multidisciplinary team should be made for           LBP. Further investigation may reveal how nonorganic
 management of any confounding factors when a                  behaviors increase and develop in patients with chronic
 patient's work tolerance fails to improve from physical       LBP. Treatment focused on prevention of the develop-
 therapy.                                                      ment of nonorganic signs may reduce the occurrence of
                                                               chronic LBP and back-related disability.
Clinical Implications
A physical problem may coexist with the presence of            Summary
nonorganic signs. Thus, the presence of nonorganic             The role of Waddell's nonorganic signs test as a screen-
signs does riot eliminate the need for a complete physi-       ing tool for psychological factors in the examination of
cal examination. A patient with a cauda equina syn-            patients with low back problems has been described. The
drome, for example, may be classified as exhibiting            presence of nonorganic signs should alert the physical
nonorganic behavior based on sensory and motor losses          therapist to the need for additional psychological tests
and overreaction to the examination because of the             and should not necessarily be considered an indicator of
intensity of symptoms. Physical examination, however,          malingering. Nonorganic signs may coexist with organic
should identify the structural etiology of the problem,        findings. An illness behavior role of the nonorganic signs
and appropriate treatment should be directed toward            is suggested, as they have been related with disability in
the pathological condition.                                    addition to physical impairments. Physical therapy man-
                                                               agement for these patients should focus on treatment of
According to Waddell et al,8 nonorganic signs by them-         illness behavior and on combating disability.
selves should not be equated with malingering or the
presence of a psychological problem. Rather, the finding
of nonorganic signs should alert the clinician to the
need for more comprehensive testing. Labeling a patient


                                                                                                               Scalzitti . 3 1 1
Physical Therapy . Volume 77 . Number 3   . March 1997
Acknowledgments                                                              19 Main CJ, Wood PLR, Hollis S, et al. The Distress and Risk Assess-
I thank Louise J White, PT, and Pamela J Woodall, PT,                        ment Method: a simple patient classification to identify distress and
                                                                             evaluate the risk of poor outcome. Spine 1992;17:42-52.
for their kind assistance with the preparation of this
update.                                                                      20 Chan CW, Goldman S, Ilstrup DM, et al. The pain drawing and
                                                                             Waddell's nonorganic physical signs in chronic low-back pain. Spine.
                                                                             1993;18:1717-1722.
References
1 Spitzer WO. Diagnosis of the problem (the problem of diagnosis):           21 Hayes B, Solyom CAE, Wing PC, Berkowitz J. Use of psychometric
scientific approach to the assessment and management of activity-            measures and nonorganic signs testing in detecting nomogenic disor-
related spinal disorders-a monograph for clinicians: report of the           ders in low back pain patients. Spine 1993;18:1254-1262,
Quebec Task Force on Spinal Disorders. Spine. 1987;12:S16-S21.
                                                                             22 Waddell G, Somerville D, Henderson I, Newton M. Objective
2 Waddell G, Main CJ, Morris EW, et al. Chronic low-back pain,               clinical evaluation of physical impairment in chronic low back pain.
psychologic distress, and illness behavior. Spine. 1984;9:209-213.           Spine. 1992;17:617-628.
3 Delitto A. Are measures of function and disability important in low        23 Hirsch G, Beach G, Cooke C, et al. Relationship between perfor-
back care? Phys Ther. 1994;74:452-462.                                       mance o n lumbar dynamometry and Waddell score in a population
                                                                             with low-back pain. Spine. 1991;16:1039-1043.
4 Bigos S, Bowyer 0 , Braen G, et al. Acute Low Back Problems in Adults:
Clinical Practice Guideline No. 14. Rockville, Md: Agency for Health Care    24 Cooke C, Menard MR, Beach GN, et al. Serial lumbar dynamometry
Policy and Research, Public Health Service, US Department of Health          in low back pain. Spine. 1992;17:653-662.
and Human Services; 1994. AHCPR publication 95-0642.
                                                                             25 Cooke C, Dusik LA, Menard MR, et al. Relationship of performance
5 Feuerstein M, Beattie P. Biobehavioral factors affecting pain and          on the ERGOS work simulator to illness behavior in a workers'
disability in low back pain: mechanisms and assessment. Phys Ther            compensation population with low back versus limb injury. J Occup
1995;75:267-280.                                                             Med. 1994;36:757-762.
6 Diagnostic and Statistical Manual of Mental Disorders. 4th ed. M'ashing-   26 Menard MR, Cooke C, Locke SR, et al. Pattern of performance in
ton, DC: American Psychiatric Association, 1994.                             workers with low back pain during a comprehensive motor perfor-
                                                                             mance evaluation. Spine. 1994;19:1359 -1 366.
7 McCahill ME. Somatoform and related disorders: delivery of diagno-
sis as first step. Am Fam Physician. 1995;52:193-203.                        27 McCulloch JA. Chemonucleolysis.] Bone Joint Surg [Br]. 1977;59:45-
                                                                             52.
8 Waddell G, McCulloch JA, Kummel E, Venner RM. Nonorganic
physical signs in low-back pain. Spine. 1980;5:117-125.                      28 Dzioba RB, Doxey NC. A prospective investigation into the ortho-
                                                                             paedic and psychologic predictors of outcome of first lumbar surgery
9 Waddell G, Richardson J. Observation of overt pain behaviour by
                                                                             following industrial injury. Spine. 1984;9:614-623.
physicians during routine clinical examination of patients with low
back pain.] Psychosom Res. 1992;36:77-87.                                    29 Waddell G, Morris EW, Di Paola MP, et al. A concept of illness
                                                                             tested as an improved basis for surgical decisions in low-back disorders.
10 Collie J. Malingering and Feigned Sickness. London, England: Edward
                                                                             Spine. 1986;11:712-719.
Arnold (Publishers) Ltd; 1913.
                                                                             30 Lehmann TR, Russell DW, Spratt KF. The impact of patients with
11 Hoover CF. A new sign for the detection of malingering and
functional paresis of the lower extremities. J A M . 1908;51:746-747.        nonorganic physical findings on a controlled trial of transcutaneous
                                                                             electrical nerve stimulation and electroacupuncture. Spine. 1983;8:
12Greenough CG, Fraser RD. Comparison of eight psychometric                  625-634.
instruments in unselected patients with back pain. Spine. 1991;16:
1068-1074.                                                                   31 Waddell G, Birchner M, Finlayson D, Main CJ. Symptoms and signs:
                                                                             physical disease or illness behaviour? BMJ. 1984;289:739-741.
13 Werneke MW, Harris DE, Lichter RL. Clinical effectiveness of
behavioral signs for screening chronic low-back pain patients in a           32 Bradish CF, Lloyd GJ, Aldam CH, et al. Do nonorganic signs help to
work-oriented physical rehabilitation program. Spine. 1993;18:2412-          predict the return to activity of patients with low-back pain? Spine.
                                                                             1988;13:557-560.
2418.
14 McCombe PF,'~airbank    JCT, Cockersole BC, Pynsent PB. Repro-            33 Lancourt J, Kettelhut M. Predicting return to work for lower back
ducibilit~ physical signs in low-back pain. Spine. 1989;14:908-918.
         of                                                                  pain patients receiving worker's compensation. Spine. 1992;17:629-
                                                                             640.
15 Solomon PE. Measurement of pain behaviour. Physiotherapy Canada.
1996;48:52-58.                                                               34 Kummel BM. Nonorganic signs of significance in low back pain.
                                                                             Spine. 1996;21:1077-1081.
16 Keefe FJ, Block AR. Development of an observation method for
assessing pain behavior in chronic low back pain patients. Behau Ther.       35 Delitto A, Erhard RE, Boling RW. A treatment-based classification
1982;13:363-375.                                                             approach to low back syndrome: identifying and staging patients for
                                                                             conservative treatment. Phys Ther. 1995;75:470-489.
17 0hlund C, Lindstrom I, Areskoug B, et al. Pain behavior in indus-
trial subacute low back pain, part I: reliability-concurrent        and      36 Marras WS, Parnianpour M, Ferguson SA, et al. The classification of
predictive validity of pain behavior assessments. Pain. 1994;58:201-209.     anatomic- and symptom-based low back disorders using motion mea-
                                                                             sure models. Spine. 1995;20:2531-2546.
18 Waddell G, Pilowsky I, Bond IMR. Clinical assessment and interpre-
tation of abnormal, illness behaviour in low back pain. Pain. 1989;39:
41-53.




                                                                                          Physical Therapy. Volume 7 7 . Number 3 . March 1997

								
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