Glenohumeral Instability

Glenohumeral instability:

excessive translation of the humeral head on the glenoid during active rotation

• involves varying degrees of injuries to dynamic and static structures that function to contain the humeral head in the glenoid

Subluxation refers to:

joint laxity, allowing for more than 50% of the humeral head to passively translate over the glenoid rim without dislocation

Dislocation is:

the complete separation of the articular surfaces of the glenoid and the humeral head

Etiology:

• combination of forces stress the anterior capsule, glenohumeral ligament, and rotator cuff, causing the humerus to move anteriorly out of the glenoid fossa

• anterior dislocation is the most common and is usually associated with shoulder abduction and lateral rotation

Signs and symptoms:

Subluxation:

• feeling the shoulder “popping” out and back into place

• pain

• paresthesias

• sensation of the arm feeling “dead”

• positive apprehension test

• capsular tenderness

• swelling

Dislocation

• severe pain

• paresthesias

• limited ROM

• weakness

• visible shoulder fullness

• arm supported by contralateral limb

Treatment:

• initial immobilization with a sling for 3-6 weeks

• RICE and NSAIDs often in the early phase

• after immobilization- ROM and isometric strengthening should be initiated followed by progressive resistive exercises emphasizing the internal and external rotators, as well as the large scapular muscles