Sulcus sign for glenohumeral instability examination technique

The sulcus sign maneuver evaluates the looseness of the glenohumeral joint. Clinicians should note that downward movement of the humeral head is influenced by the tone and bulk of the deltoid, the tone and thickness of the supraspinatus muscle and tendon, and the structure and integrity of the glenohumeral capsule. Therefore, it is important to compare shoulders.