The Shoulder



The shoulder is one of the most commonly injured joints in the body.

Four bones involved:

  • humerus,
  • scapula,
  • clavicle,
  • and first rib.

“SITS” muscles (rotator cuff): supraspinatus, infraspinatus, teres minor, and subscapularis The subacromial space contains the tendons of the rotator cuff and biceps and the subacromial bursa.

The coracoacromial arch creates a functional space that is occupied by the tendons of the rotator cuff, biceps, and subdeltoid bursa. Impingement is increased by internal rotation of the humerus, which jams the greater tuberosity under the coracoacromial arch.

Range of Motion

Capsular Pattern- lateral rotation, ABD, medial rotation

  • Flexion: 160°- 180° Extension: 50-60°
  • Medial rotation: 60-100°
  • Lateral Rotation: 80-90°
  • Adduction (ADD): 50-75°
  • Abduction (ABD): 160- 180° Muscles
  • Abduction: supraspinatus (0-35°) and deltoids.

Adduction: pectoralis major, latisimus dorsi, and both teres minor and major. Lateral (external) rotation: infraspinatus and teres minor.

Medial (internal) rotation: subscapularis, pectoralis major, lats, and teres major Resisted forward flexion: ant.

Deltoid, pectoralis major, and coracobrachialis

Resisted extension: posterior deltoid, lats, and pectoralis major.

Stabilizer: serratus anterior; most important stabilizer of the of the shoulder complex Ligaments The glenoid labrum is a fibrocartilagenous ring that attaches to the outer margin of the glenoid fossa; it helps to deepen the socket.

Tendons

Tendons are tough cords of tissue that connect muscle to bone. In the shoulder, the major tendons that create stability to the shoulder are the “SITS” muscles. As ligaments do not create much stability, the shoulder relies heavily on the tendons to provide support. Often if one injures their shoulder they become more susceptible to further injury as the tendons have increased dramatically in their laxity.

Orthopedic Tests

Tendons Painful arc- passive or active ABD (pain thru 70- 110 degrees with less or no pain before or after this range is positive) Yergason’s- bicipital tendonitis (flex pt elbow; pt attempts to resist E and SUP of forearm) Speed’s- bicipital tendonitis (pt flexes and supinates fully E’d arm; examiner provides resistance) Drop arm- tear in cuff (examiner raises pt arms to 90° ABD and suddenly drops arm) Empty can- supraspinatus tear Neer’s- supraspinatus tendon impingement (arm forcibly ABD thru flexion) Hawkin’s-Kennedy- supraspinatus impingement (forward flexion to 90° and med rot) Lift off- subscapularis Apley’s scratch and bra line test- rotator cuff (supraspinatus degenerative tendonitis)

Anterior instability Load and shift- move humeral head anterior while pt seated Crank- ABD 90° and laterally rotate Rowe- while patient supine w/ hand behind humeral head drawing forward Fulcrum- crank arm into internal rotation while hand stabilizes behind humeral head

Posterior instability Posterior apprehension Push/pull- supine pt with elbow flexed 90°. Ext Rt and ABD arm to 90°; pull on wrist while pushing on proximal humerus Jerk (seated Norwood) - pt arm forward flexed to 90° with elbow also flexed to 90°. Examiner directs PA force thru shoulder while horizontally ADD the arm Labral Tear Clunk test- ABD shoulder to 120°.

Examiner applies AP force to humeral head while circumducting shoulder. Anterior slide SLAP test- pt’s shoulder is ABD and ext rotated (palm up) with elbow extended. Downward pressure applied to proximal forearm as pt resists. AC injury AC compression Horizontal ADD