The glenohumeral joint capsule surrounds the entire shoulder joint, attaching proximally to the glenoid labrum and neck and distally to the anatomical neck of the humerus. It is extraordinarily lax compared to other joint capsules, being twice the surface area needed to contain the humeral head, which allows the remarkable range of shoulder motion. The inferior capsule becomes the most important stabilising structure in the abducted and externally rotated position.
| Origin | Glenoid labrum and glenoid neck |
|---|---|
| Insertion | Anatomical neck of the humerus |
| Actions | Provides passive containment of the humeral head within the glenoid; becomes taut at extremes of motion to limit translation |
|---|
Adhesive capsulitis (frozen shoulder) involves progressive fibrosis and contracture of the glenohumeral capsule, particularly the rotator interval and inferior capsular pouch, producing the characteristic pain and stiffness pattern of frozen shoulder. The rotator interval between the supraspinatus and subscapularis is the first region to contract and produces the characteristic loss of external rotation with the arm at the side that distinguishes frozen shoulder from rotator cuff pathology.
Progressive glenohumeral capsular contracture producing the painful and then stiff phases of frozen shoulder, managed with physiotherapy, corticosteroid injection, hydrodilatation, or arthroscopic capsular release in refractory cases.
Isolated posterior capsule tightness producing glenohumeral internal rotation deficit in throwing athletes, contributing to SLAP tears and posterior labral pathology, managed with posterior capsular stretching.
