The posterior band of the IGHL is the posterior portion of the hammock-like inferior glenohumeral ligament, resisting posterior humeral head translation when the arm is in the throwing follow-through position. Contracture of the posterior band (common in throwers) produces GIRD — glenohumeral internal rotation deficit — by posteriorly tightening the capsule, which shifts the humeral head posterosuperiorly during the late cocking phase.
| Origin | Posterior inferior glenoid labrum (6-9 o'clock position) |
|---|---|
| Insertion | Posterior inferior humeral neck |
| Actions | Restrains posterior glenohumeral translation in the abducted and internally rotated position |
|---|
GIRD from posterior IGHL posterior band contracture is the primary mechanical contributor to SLAP tears and internal impingement in overhead athletes. The sleeper stretch (horizontal adduction in side-lying) specifically stretches the posterior IGHL posterior band. Total rotational arc preservation (increased external rotation compensating for reduced internal rotation) rather than symmetric rotation is the current benchmark for throwing athlete shoulder management.
Posterior IGHL band contracture reducing internal rotation in throwing athletes, contributing to internal impingement and SLAP tears managed with posterior capsular stretching.
