Which muscle is an antagonist to the latissimus dorsi during adduction of the shoulder?

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

Answer: (A)

Antagonists oppose the movement a muscle produces. Latissimus dorsi brings the arm toward the body (adduction) along with extension and internal rotation. The muscle that counteracts that adduction is one that produces abduction. Supraspinatus is the primary initiator of shoulder abduction, especially in the initial range of motion, so it actively opposes the latissimus dorsi during adduction. That direct opposing action makes supraspinatus the best antagonist in this context. The other rotator cuff muscles mainly rotate the shoulder (infraspinatus and teres minor externally; subscapularis internally) and don’t oppose adduction as their primary role, so they’re not the best match here.