In this medical test, patient is positioned supine, shoulder in abduction to 90 degrees with elbow in flexion to 90 degrees. Then the shoulder is externally rotated until the patient becomes apprehensive (apprehension sign). The amount of external rotation at the onset of apprehension is noted. The shoulder is brought back to resting position and the shoulder external rotation is repeated, this time with posteriorly directed force over the humeral head. The amount of external rotation when the patient becomes apprehensive is again noted. The test is considered positive if the external rotation range with posteriorly directed stress over the humeral head is greater than when there is no posteriorly directed stress.