The Drop Arm test assesses dysfunction of which rotator cuff muscle?

• A. Teres minor
• B. Subscapularis
• C. Infraspinatus
• D. Supraspinatus

Answer: (D)

The Drop Arm test targets the supraspinatus region of the rotator cuff. When the arm is placed in about 90 degrees of abduction and the person is asked to slowly lower it, a normal response is a smooth, controlled descent. If the arm cannot be held at that position, or it drops suddenly with pain, that suggests supraspinatus tendon pathology or tear. The other rotator cuff muscles aren’t primarily challenged by this maneuver: infraspinatus is tested with resisted external rotation, subscapularis with internal rotation/lift-off tests, and teres minor also contributes to external rotation but is not the focus here. Therefore, a positive Drop Arm test most strongly indicates supraspinatus dysfunction.