Stability in the glenohumeral joint

Stability in the glenohumeral joint is preserved by passive and active structures. The glenoid labrum limits translations of the humeral head and supports the concavity compression mechanism by increasing the depth of the glenoid fossa. The most common injury to the labrum is the superior labrum anterior posterior (SLAP) tear; this condition is common in overhead throwing athletes, due to alterations in shoulder kinematics and repetitive end-range stresses imparted on the glenohumeral joint.

Several theories propose mechanisms that may cause SLAP tears: they might be the result of either a deceleration traction or a “peel-back” injury from the tendon of the long head of the biceps. Another potential cause could be a superior migration of the humeral head as a result of contracture of the posterior capsule, also leading to the condition referred to as a glenohumeral internal rotation deficit (GIRD). 

Physical examination should contain an assessment of the glenohumeral and scapular range of motion and kinematics, and strength testing of especially the rotator cuff muscles. Although specific tests cannot accurately diagnose SLAP lesions, either alone or as a cluster, the active compression (O’Briens) test, the crank test and Speed’s test are the most sensitive. Nonoperative management should be aimed at improving muscle strength and endurance and restoring glenohumeral and scapulothoracic motion; exercises are initiated preferrably after pain has resolved. > From: Knesek et al., Am J Sports Med 41 (2013) 444-460. All rights reserved to The Author(s).