Drop-arm test is most indicative of tear of which muscle?

Drop-arm test is most indicative of tear of which muscle?

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

Answer: (D)

The drop-arm test targets the supraspinatus tendon. When you raise the arm to about 90 degrees in the scapular plane, the supraspinatus normally helps initiate abduction and, importantly, eccentrically controls the lowering of the arm as the deltoid continues the movement. If the supraspinatus is torn, this control is lost, so the arm cannot be lowered smoothly and may suddenly drop or be painfully difficult to lower. This makes the test particularly sensitive to supraspinatus pathology. Other rotator cuff muscles have different primary roles—ex: the infraspinatus and teres minor are external rotators, and the subscapularis is an internal rotator. Tests that isolate those actions (like resisted external rotation or lift-off/internal rotation tests) assess their integrity, whereas the drop-arm maneuver specifically stresses the supraspinatus function during the transition from active elevation to lowering.

The drop-arm test targets the supraspinatus tendon. When you raise the arm to about 90 degrees in the scapular plane, the supraspinatus normally helps initiate abduction and, importantly, eccentrically controls the lowering of the arm as the deltoid continues the movement. If the supraspinatus is torn, this control is lost, so the arm cannot be lowered smoothly and may suddenly drop or be painfully difficult to lower. This makes the test particularly sensitive to supraspinatus pathology.

Other rotator cuff muscles have different primary roles—ex: the infraspinatus and teres minor are external rotators, and the subscapularis is an internal rotator. Tests that isolate those actions (like resisted external rotation or lift-off/internal rotation tests) assess their integrity, whereas the drop-arm maneuver specifically stresses the supraspinatus function during the transition from active elevation to lowering.