Shoulder

Swelling of the shoulder joint may be visible due to a joint effusion, or synovial thickening. Deformity of the joint and fractures and dislocations are usually obvious (figure 37a,b). Table 4 provides details of the muscles of the shoulder and figure 38a–d illustrations of the anterior and posterior bones and muscles of the upper limb.

Table 4 Muscles of the shoulder joint and upper arm

Shoulder

  1. Sternal and clavicular heads of sternomastoid
  2. Clavicular and acromial attachments of trapezius
  3. Sternal and clavicular heads of pectoralis major, and laterally to outer lip of bicipital groove.
  4. Clavicular and acromial attachments of deltoid: distally to midshaft humerus.
  5. Pectoralis minor
  6. Coracobrachialis: distally to medial humeral midshaft
  7. Short head of biceps
  8. Supraspinatus
  9. Subscapularis
  10. Long head of triceps
  11. Latissimus dorsi: rotates around teres major to floor of bicipital groove
  12. Teres major
  13. Brachioradialis
  14. Brachialis
  15. Extensor carpi radialis longus
  16. Common extensor origin
  17. Pronator teres: distally to lateral radial midshaft
  18. Common flexor origin
  19. Flexor digitorum superficialis: distal split onto middle phalanx
  20. Supinator: from lateral ulna around posterior aspect of upper radius
  21. Ulnar head of pronator teres
  22. Radial attachment of biceps
  23. Flexor digitorum profundus: to distal phalanx
  24. Flexor pollicis longus: to base of distal phalanx
  25. Pronator quadratus: between adjacent radius and ulna
  26. Flexor carpi ulnaris
  27. Abductor pollicis longus
  28. Tendons of extensor carpi radialis longus and brevis
  29. Extensor pollicis brevis
  30. Extensor pollicis longus

  1. Sternal and clavicular heads of sternomastoid
  2. Trapezius 
  3. Brachial plexus 
  4. Subclavian artery
  5. Sternal and clavicular heads of pectoralis major
  6. Deltoid
  7. Axillary artery
  8. Biceps, short head
  9. Biceps, long head
  10. Serratus anterior
  11. Median nerve
  12. Radial nerve
  13. Brachial artery
  14. Common flexor origin
  15. Brachioradialis
  16. Pronator teres
  17. Biceps tendon and aponeurosis
  18. Flexor carpi ulnaris
  19. Flexor carpi radialis
  20. Ulnar artery
  21. Radial artery
  22. Palmaris longus, overlying median nerve at wrist
  23. Ulnar nerve
  24. Thenar muscles
  25. Hypothenar muscles

  1. Levator scapulae
  2. Coracoid process
  3. Trapezius
  4. Supraspinatus
  5. Deltoid: spine and acromion, to
  6. Infraspinatus
  7. Rhomboideus minor and major
  8. Teres minor
  9. Infraspinatus
  10. Long head of triceps
  11. Teres minor
  12. Rhomboideus minor and major
  13. Lateral heads of triceps
  14. Deltoid tuberosity of humerus
  15. Teres major
  16. Latissimus dorsi
  17. Medial heads of triceps
  18. Anconeus
  19. Anconeus
  20. Supinator
  21. Linear attachment on subcutaneous border of ulna of extensor carpi ulnaris, flexor carpi ulnaris and flexor digitorum profundus
  22. Abductor pollicis longus
  23. Extensor pollicis longus
  24. Extensor pollicis brevis
  25. Extensor indicis
  26. Extensor carpi radialis longus
  27. Extensor carpi radialis brevis
  28. Extensor carpi ulnaris (through pisometacarpal ligament)
  29. Extensor pollicis longus
  30. Extensor digitorum longus

Upper limb anatomy: posterior muscles Figure 38d Upper limb anatomy: posterior muscles

  1. Trapezius
  2. Acromion
  3. Spine of scapula
  4. Deltoid
  5. Infraspinatus
  6. Axillary nerve: impalpable but important relation to surgical neck of  humerus
  7. Teres minor
  8. Teres major
  9. Long head of triceps
  10. Radial nerve: palpable through the fibres of triceps
  11. Latissimus dorsi
  12. Tendon to upper border of olecranon
  13. Lateral epicondyle
  14. Ulnar nerve: lying on back of medial epicondyle
  15. Olecranon process
  16. Anconeus
  17. Brachioradialis and common extensor muscles
  18. Common flexor muscles
  19. Extensor digitorum longus
  20. Extensor carpi ulnaris
  21. Abductor pollicis longus
  22. Extensor pollicis brevis
  23. Tendons of extensor carpi radialis longus and brevis
  24. Extensor pollicis longus
  25. Dorsal digital expansion over metacarpophalangeal joints

The shoulder joint allows flexion, extension, abduction, adduction, external and internal rotation and circumduction. Flexion (figure 39a,b) is possible to 180 degrees when the arm is swung forward as in marching. This involves some scapular movement, the glenohumeral joint contributing about 90 degrees. Extension (figure 39c,d) of the shoulder is possible to 65 degrees, when the arm is swung backwards.

Arm abduction takes place at both the glenohumeral joint and through scapular rotation. On its own, assessed by fixing the scapular, the former is to 90 degrees (figure 40a,b).

When the movement of the scapular is included 180 degrees are possible, however, there is also external rotation of the shoulder joint for the greater tuberosity to clear the acromion. The scapular movement in abduction can be observed from behind, noting the position of the inferior angle, at rest, at 90 degrees and 180 degrees abduction (figure 41a–c).

The pectoralis major and lattissimus dorsi muscles are powerful adductors from the abducted position, as in raising the body from an overhead bar, pulling objects towards you and in the follow through of a tennis serve. They can be tested and palpated by asking the subject to press their hands together (figure 42) or downwards on their hips

Adduction (figure 43a,b) is possible to 50 degrees in a normal joint, when the elbow is carried forward across the front of the chest.

External rotation (figure 44a–c) is to 60 degrees. This is assessed with a flexed elbow, placing the hand behind the head. The movement, however, combines abduction with external rotation.

Internal rotation of the shoulder joint is stopped when the flexed forearm meets the trunk. However, resisted movement can be tested in this position (figure 45a,b); ask the subject to scratch the middle of their back, with the thumb as high as possible, to check the full rotation of 90 degrees (figure 45c).