11.14.10. Muscles of the shoulder_ back_ and arms

Document Sample
11.14.10. Muscles of the shoulder_ back_ and arms Powered By Docstoc
					                                                                  Muscles of the Shoulder, Back, and Upper Arm

    Muscle           Medial Attachment      Lateral Attachment            Function           Innervation         Diagram
Trapezius          Medial third of          Lateral third of       Descending part        Spinal accessory
                   superior nuchal line;    clavicle; acromion     elevates; ascending    nerve (CN XI)
                   external occipital       and spine of           part depresses; and    (motor fibers)
                   protuberance; nuchal     scapula                middle part (or all    and C3, C4
                   ligament; spinous                               parts together)        spinal nerves
                   processes of C7-T12                             retracts scapula;      (pain and
                   vertebrae                                       descending and         proprioceptive
                                                                   ascending parts act    fibers)
                                                                   together to rotate
                                                                   glenoid cavity

Levator scapulae   Posterior tubercles of   Medial border of       Elevates scapula and   Dorsal scapular
                   transverse processes     scapula superior to    tilts its glenoid      (C5) and
                   of C1-C4 vertebrae       root of scapular       cavity inferiorly by   cervical (C3,
                                            spine                  rotating scapula       C4) nerves
Deltoid          Lateral third of       Deltoid tuberosity     Clavicular (anterior)   Axillary nerve
                 clavicle; acromion     of humerus             part: flexes and        (C5,C6)
                 and spine of scapula                          medially rotates arm
                                                               Acromial (middle)
                                                               part: abducts arm
                                                               Spinal (posterior)
                                                               part: extends and
                                                               laterally rotates arm

Rhomboid major   Spinous processes of   Medial border of       Retract scapula and     Dorsal scapular
                 T2-T5 vertebrae        scapula from level     rotate it to depress    nerve (C4,C5)
                                        of spine to inferior   glenoid cavity; fix
                                        angle                  scapula to thoracic
Rhomboid minor   Nuchal ligament;       Smooth triangular      Retract scapula and     Dorsal scapular
                 spinous processes of   area at medial end     rotate it to depress    nerve (C4,C5)
                 C7 and T1 vertebrae    of scapular spine      glenoid cavity; fix
                                                               scapula to thoracic

Teres major      Posterior surface of   Medial lip of          Adducts arm and         Lower
                 inferior angle of      intertubercular        medially rotates arm    subscapular
                 scapula                sulcus of humerus                              nerve (C5, C6)
Teres minor        Middle part of lateral   Inferior facet of     Laterally rotates       Axillary nerve
                   border of scapula        greater tubercle of   arm; and acts with      C5, (C6)
                                            humerus               rotator cuff muscles

Subscapularis      Subscapular fossa        Lesser tubercle of    Medially rotates        Upper and lower
                   (most of anterior        humerus               arm; as part of         subscapular
                   surface of scapula)                            rotator cuff, helps     nerves (C5, C6,
                                                                  hold head of            C7)
                                                                  humerus in glenoid
Supraspinatus      Supraspinous fossa       Superior facet of     Initiates and assists   Suprascapular
                   of scapula               greater tubercle of   deltoid in abduction    nerve
                                            humerus               of arm and acts with    (C4), C5,(C6)
                                                                  rotator cuff muscles
Infraspinatus      Infraspinous fossa of    Middle facet of       Laterally rotates       Suprascapular
                   scapula                  greater tubercle of   arm; acts with          nerve C5, (C6)
                                            humerus               rotator cuff muscles
Pectoralis major   Clavicular head—         Lateral lip of        Adducts and             Lateral and
                   anterior surface of      intertubercular       medially rotates        medial pectoral
                   medial half of           sulcus (groove) of    humerus; draws          nerves;
                   clavicle.                humerus               scapula anteriorly      clavicular head
                   Sternocostal head—                             and inferiorly.         (C5),C6;
                   anterior surface of                            Acting alone,           sternocostal
                   sternum, superior six                          clavicular head         head C7,C8,(T1)
                   costal cartilages,                             flexes humerus and
                   aponeurosis of                                 sterocostal head
                   external oblique                               extends it from the
                   muscle                                         flexed position
Pectoralis minor    3rd-5th ribs near the      Medial border and     Stabilizes scapula by    Medial pectoral
                    costal cartilage           superior surface of   drawing inferiorly       nerve (C8,T1)
                                               coracoids process     and anteriorly
                                               of the scapula        against thoracic wall

Serratus anterior   External surface of        Anterior surface of   Protracts scapula,       Long thoracic
                    lateral parts of ribs 1-   medial border of      holds it against the     nerve—
                    8                          the scapula           thoracic wall, rotates   (C5),C6,C7
                                                                     it upward
Latissimus dorsi   Spinous processes of       Floor of              Extends, adducts,        Thoracodorsal
                   inferior 6 thoracic        intertubercular       and medially rotates     nerve C6, C7,
                   vertebrae,                 sulcus of humerus     humerus; raises body     (C8)
                   thoracolumbar                                    toward arms during
                   fascia, iliac crest, and                         climbing
                   inferior 3 or 4 ribs

Subclavius         Junction of first rib      Inferior surface of   Anchors and              Subclavian
                   and its costal             the middle third of   depresses clavicle       nerve C5,(C6)
                   cartilage                  clavicle

Biceps brachii     Short head: tip of         Biceps tendon:        Supinates forearm        Musculocutaneo
                   coracoid process of        radial tuberosity     and, when it is          us nerve (C5,
                   scapula                    Bicipital             supine. flexes           C6, C7)
                   Long head:                 aponeurosis: deep     forearm; short head
                   supraglenoid tubercle      fascia over medial    resists dislocation of
                   of scapula                 forearm mm            shoulder
Coracobrachialis   Tip of coracoid            Middle third of       Helps flex and           Musculocutaneo
                   process of scapula         medial surface of     adduct arm; resists      us nerve (C5,
                                              humerus               dislocation of           C6, C7)
Brachialis         Distal half of anterior    ulnar tuberosity      Flexes forearm in all    Musculocutaneo
                   surface of humerus         (and ulnar            positions                us nerveb (C5,
                                              tuberosity)                                    C6) and radial
                                                                                             nerve (C5, C7)
Triceps brachii   Long head:              Proximal end of        Chief extensor of        Radial nerve
                  infraglenoid tubercle   olecranon of ulna      forearm; long head       (C6, C7, C8)
                  of scapula              (and fascia of         resists dislocation of
                  (Lateral head:          forearm)               humerus; especially
                  posterior surface of                           important during
                  humerus, superior to                           adduction
                  radial groove
                  Medial head:
                  posterior surface of
                  humerus, inferior to
                  radial groove)

Anconeus          Lateral epicondyle of   Lateral surface of     Assists triceps in       Radial nerve
                  humerus                 olecranon and          extending forearm;       (C7, C8, T1)
                                          superior part of       stabilizes elbow
                                          posterior surface of   joint; may abduct
                                          ulna                   ulna during
Pronator Teres   Ulnear head:           Middle convexity        Pronates and flexes   Median nerve
                 coronoid process       of lateral surface of   forearm (at elbow)    (C6, C7)
                 Humaral head:
                 Medial epicondyle of
                 the humerous

Flexor Carpi     Medial epicondyle of   Base of second          Flexes and abducts    Median nerve
Radialis (FCR)   the humerus            metacarpal              hand (at wrist)       (C6, C7)
Palmaris longus   Medial epicondyle of    Distal half of flexor   Flexes hand (at      Median Nerve
                  the humerus             retinaculum and         wrist) and tenses    (C7, C8)
                                          apex of palmar          palmar aponeurosis

Flexor Carpi      Medial epicondyle of    Pisiform, hook of       Flexes and adducts   Ulnar nerve (C7,
Ulnaris (FCU)     the humerus             hamate, 5th             hand (at wrist)      C8)
                  Olecranon and
                  posterior border (via
Flexor Digitorum   Humeroulnar head:       Shafts of middle     Flexes middle           Median nerve
Superficialis      Medial epicondyle of    phalanges of         phalanges at            (C7, C8, T1)
                   humerous (common        medial four digits   proximal
                   flexor orgin) and                            interphalangeal
                   coronoid process of                          joints of middle four
                   ulna                                         digits; acting more
                                                                strongly, it also
                   Radial Head:                                 flexes proximal
                   Proximal Radius                              phalanges at
                   (superior half of                            metacarpophalangeal
                   anterior border)                             joints

Flexor Digitorum   Proximal three          Medial Part:         Medial Part:            Medial Part:
Profundus (FDP)    quarters of medial      Bases of distal      Flexes distal           Ulnar Nerve
                   and anterior surfaces   phalanges of 4th     phalanges 4 and 5 at    (C8, T1)
                   of ulna and             and 5th digits       distal
                   interosseous                                 interphalangeal
                   membrane                                     joints

                                           Lateral Part:        Lateral part            Lateral part:
                                           Bases of distal      Flexes distal           Anterior
                                           phalanges of 2nd     phalanges 2 and 3 at    interosseous
                                           and 3rd digits       distal                  nerve, from
                                                                interphalangeal         median nerve
                                                                joints                  (C8, T1)
Flexor Pollicis   Anterior surface of   Base of distal        Flexes phalanges of   Anterior
Longus (FPL)      radius and adjacent   phalanx of thumb      1st digit (thumb)     interosseous
                  interosseous                                                      nerve, from
                  membrane                                                          median nerve
                                                                                    (C8, T1)

Pronator          Distal quarter of     Distal quarter of     Pronates forearm;     Anterior
quadrates         anterior surface of   anterior surface of   deep fibers bind      interosseous
                  ulna                  radius                radius and ulna       nerve, from
                                                              together              median nerve
                                                                                    (C8, T1)
Brachioradialis   Proximal two thirds   Lateral surface of     Relatively weak         Radial nerve
                  of the lateral        distal end of radius   flexion of the          (C5, C6, C7)
                  supraepicondylar      proximal to styloid    forearm; maximal
                  ridge of humerus      process                when forearm is in
                                                               position (Forms the
                                                               lateral border of the
                                                               cubital fossa

Extensor carpi    Lateral               Dorsal aspect of       Extend and abduct       Radial Nerve
radialis longus   supraepicondylar      base of 2nd            hand at the wrist       (C6, C7)
(ECRL)            ridge of humerus      metacarpal             joint; Active during
                                                               fist clenching
Extensor carpi    Lateral epicondyle of   Dorsal aspect of     Extend and abduct        Deep branch of
radialis breves   humerus (common         base of 3rd          hand at the wrist        the radial nerve
(ECRB)            extensor origin)        metacarpal           joint                    (C7, C8)

Extensor          Lateral epicondyle of   Extensor             Extends medial four      Deep branch of
digitorum         humerus (common         expansions of        digits primarily at      the radial nerve
                  extensor origin)        medial four digits   the                      (C7, C8)
                                                               joints, secondarily at
                                                               the interphalangeal
Extensor digiti   Lateral epicondyle of   Extensor expansion   Extends 5th digit        Deep branch of
minimi (EDM)      humerus (common         of 5th digit         primarily at             the radial nerve
                  extensor origin)                             metacarpophalangeal      (C7, C8)
                                                               joints, secondarily at

Extensor Carpi    Lateral epicondyle of   Dorsal aspect of     Extends and adducts      Deep branch of
Ulnaris           humerus; posterior      base of 5th          hand at wrist joint      the radial nerve
                  border of ulna via a    metacarpal           (also active during      (C7, C8)
                  shared apneurosis                            fist clenching)
Supinator          Lateral epicondyle of   Lateral, posterior,   Supinates forearm;       Deep branch of
                   humerus; radial         and anterior          rotates radius to turn   radial nerve (C7,
                   collateral and anular   surfaces of           palm anteriorly or       C8)
                   ligaments; supinator    proximal third of     superiorly (if elbow
                   fossa; crest of ulna    radius                is flexed)

Extensor indicis   Posterior surface of    Extensor expansion    Extends 2nd digit        Posterior
                   distal third of ulna    of 2nd digit          (enabling its            interosseous
                   and interosseous                              independent              nerve (C7, C8),
                   membrane                                      extension); helps        continuation of
                                                                 extend hand at wrist     deep branch of
                                                                                          radial nerve
Abductor Pollicis   Posterior surface of     Base of 1st        Abducts thumb and        Posterior
Longus (APL)        proximal halves of       metacarpal         extends it at            interosseus
                    ulna, radius, and                           carpometacarpal          nerve (C7, C8),
                    interosseous                                joint                    continuation of
                    membrane                                                             deep branch of
                                                                                         radial nerve

Extensor Pollicis   Posterior surface of     Dorsal aspect of   Extends distal           Posterior
Longus              middle third of ulna     base of distal     phalanx of thumb ant     interosseus
                    and interosseous         phalanx of thumb   interphalangeal joint;   nerve (C7, C8),
                    membrane                                    extends                  continuation of
                                                                metacarpoplangeal        deep branch of
                                                                and carpometacarpal      radial nerve
Extensor Pollicis   Posterior surface of     Dorsal aspect of   Extends proximal         Posterior
Brevis              distal third of radius   base of proximal   phalanx of thumb at      interosseus
                    and interosseus          phalanx of thumb   matacarpophalangeal      nerve (C7, C8),
                    membrane                                    joint; extends           continuation of
                                                                carpometacarpal          deep branch of
                                                                joint                    radial nerve
Opponens            Flexor retinaculum   1st metacarpal         To oppose thumb, it     Recurrent
pollicis            and tubercles of     (lateral side)         draws 1st metacarpal    branch of
                    scaphoid and                                medially to center of   median nerve
                    trapezium                                   palm and rotates it     (C8, T1)

Abductor pollicis   Flexor retinaculum   Base of proximal       Adducts thumb;          Recurrent
brevis              and tubercles of     phalanx of thumb       helps to oppose it      branch of
                    scaphoid and         (lateral side)                                 median nerve
                    trapezium                                                           (C8, T1)
Flexor pollicis     Flexor retinaculum   Base of proximal       Superficial head:       Superficial head:
brevis              and tubercles of     phalanx of thumb       Flexes thumb            Recurrent
                    scaphoid and         (lateral side)                                 branch of
                    trapezium                                                           median nerve
                                                                                        (C8, T1)

                                                                Deep head:              Deep head:
                                                                Adducts thumb           Deep branch of
                                                                toward lateral border   ulnar nerve (C8,
                                                                of palm                 T1)
Abductor digiti     Pisiform             Base of proximal       Abducts 5th digit;      Deep branch of
minimi                                   phalanx of 5th digit   assists in flexion of   ulnar nerve (C8,
                                         (medial side)          its proximal phalanx    T1)
Flexor digiti       Hook of hamate and   Base of proximal       Flexes proximal         Deep branch of
minimi brevis       flexor retinaculum   phalanx of 5th digit   phalanx of 5th digit    ulnar nerve (C8,
                                         (medial side)                                  T1)
Opponens digiti     Hook of hamate and    5th metacarpal        Draws 5th metacarpal     Deep branch of
minimi              flexor retinaculum    (medial border)       anterior and rotates     ulnar nerve (C8,
                                                                it, bringing 5th digit   T1)
                                                                into opposition with

Adductor pollicis   Oblique head: Bases   Medial side of base   Adducts thumb            Deep branch of
                    of 2nd and 3rd        of proximal           towards lateral          ulnar nerve (C8,
                    metacarpals,          phalanx of thumb      border of palm           T1)
                    capitates, and
                    adjacent carpals

                    Transverse head:
                    Anterior surface of
                    shaft of 3rd
Lumbricles (4)      1st and 2nd:           Lateral (thumb)       Flex                       1st and 2nd:
                    Lateral two tendons    sides of extensor     metacarpophalangeal        Median nerve
                    of flexor digitorum    expansions of 2nd-    joints; extends            (C8, T1)
                    profundus (as          5th digits            interphalangeal
                    unipennate muscles)                          joints of 2nd-5th digits   3rd and 4th:
                                                                                            Deep branch of
                    3rd and 4th:                                                            ulnar nerve (C8,
                    Medial three tendons                                                    T1)
                    of flexor digitorum
                    profundus (as
                    bipennate muscles)

                                                                                                                (Palmar View)
Dorsal interossei   Adjacent sides of      Bases of proximal     Abduct 2nd-4th digits      Deep branch of
(4)                 two metacarpals (as    phalanges; extensor   from axial line; act       ulnar nerve (C8,
                    bipennate muscles)     expansions of 2nd-    with lumbricles in         T1)
                                           4th digits            flexing
                                                                 joints and extending

                                                                                                                (Palmar View)
Palmar interossei   Palmer surface of      Bases of proximal     Adduct 2nd, 4th, and       Deep branch of
(3)                 2nd, 3th, and 4th      phalanges; extensor   5th digits toward          ulnar nerve (C8,
                    metacarpals (as        expansions of 2nd,    axial line; assists        T1)
                    unipennate muscles)    4th, and 5th digits   lumbricals in flexing
                                                                 joints and extending
                                                                 joints; extensor
                                                                 expansions of 2nd-4th

                                                                                                               (Palmar View)

Shared By:
xuxianglp xuxianglp http://