Sulcus Sign (Shoulder)
The sulcus sign indicates inferior instability of the glenohumeral joint. To perform this test, have the patient seated with her arm relaxed. With one hand, palpate the inferior aspect of the acromion and the superior aspect of the humeral head. With the other hand, grasp the arm proximal to the elbow and pull down. The test is positive if there is significant downward displacement of the humeral head, creating a visible sulcus below the acromion.