The posterior glenohumeral capsule and posterior IGHL limit posterior humeral head translation. Posterior capsular contracture — excessive tightening of the posterior capsule — is the primary cause of glenohumeral internal rotation deficit (GIRD) in throwing athletes, producing a loss of internal rotation compared to the non-dominant side. GIRD shifts the humeral head posterosuperiorly during the late cocking phase of throwing, producing posterior impingement and SLAP tears.
| Origin | Posterior glenoid labrum |
|---|---|
| Insertion | Posterior anatomical neck of the humerus |
| Actions | Restrains posterior glenohumeral translation; becomes taut in horizontal adduction and internal rotation; limits cross-body reach |
|---|
Sleeper stretch (horizontal adduction in side-lying) specifically targets the posterior capsule and is the primary conservative treatment for GIRD and throwing-related shoulder pathology. Posterior capsular release is performed arthroscopically for capsular contracture refractory to stretching.
GIRD from posterior capsule tightness in throwers producing posterior impingement and SLAP tears managed with sleeper stretch and posterior capsular release for refractory contracture.
