Rotator Interval Capsule

capsula intervalli rotatorum

The rotator interval is a triangular region of the glenohumeral capsule between the anterior supraspinatus and the superior subscapularis, reinforced by the coracohumeral ligament and superior glenohumeral ligament.

Region: Shoulder

Biomechanics

Function & Actions

Provides anterior superior shoulder stability, limits inferior and posterior glenohumeral subluxation, constrains external rotation in adduction, and forms the roof of the biceps tendon as it enters the groove.

Clinical Relevance

Clinical Notes

Rotator interval closure is performed in shoulder instability surgery to reduce inferior and posterior subluxation when present. Excessive rotator interval contracture restricts external rotation — a complication of over-tightening in instability repair. In adhesive capsulitis, the rotator interval is the first and most affected site of capsular contraction.

Pathology

Common Injuries & Conditions

Rotator Interval Closure for Inferior Instability

Suturing the anterior supraspinatus to the subscapularis across the interval reduces posterior and inferior glenohumeral subluxation in multidirectional instability surgery.

Rotator Interval Contracture in Frozen Shoulder

Adhesive capsulitis predominantly contracts the rotator interval, producing external rotation loss at the side — the first movement lost and the last to recover.