Which muscle extends, adducts, and medially rotates the shoulder and is strengthened by band rows?

• A. Deltoid
• B. Trapezius
• C. Infraspinatus
• D. Latissimus Dorsi

Answer: (D)

Latissimus dorsi is the muscle that extends, adducts, and medially rotates the shoulder. In a band-row pulling motion, you pull the arms back toward your torso with the elbows kept close to the body. That combination of pulling back (extension), bringing the arm toward the midline (adduction), and turning the arm inward (medial rotation) is exactly what the latissimus dorsi does. Band rows strongly engage the lats because they’re a primary mover in pulling movements that bring the arm down and back.

The other muscles shown don’t match all three actions together. The deltoid mainly abducts the arm; the trapezius helps move and stabilize the shoulder blades but doesn’t provide the arm-extending, adducting, and inward-rotating action by itself; the infraspinatus mainly externally rotates and stabilizes the shoulder rather than extending and adducting it.