Shoulder

Glenohumeral instability

Mechanism

In the traumatic form the head dislocates anteroinferiorly on abduction with external rotation, tearing the labrum anteriorly. In the atraumatic form the capsule is too capacious without a clear event.

Recognition

A positive apprehension test in abduction with external rotation, where the sign is not pain but the fear of the shoulder shifting out. The hyperabduction test shows whether the inferior capsule is too lax.

Course

The younger at first dislocation, the greater the chance of recurrence; under twenty that rises to the majority. In atraumatic instability exercise therapy is first choice and surgery rarely the answer.

Structures

• Glenoid labrum
• Glenohumeral ligaments (Superior, Middle, and Inferior / IGHL complex)
• Subscapularis

Joints involved

• Shoulder joint (glenohumeral joint)

Clinical tests

• Shoulder apprehension test
• Hyperabduction test

Sources

• Magee DJ, Manske RC. Orthopedic Physical Assessment, 7e editie. Elsevier. 2021