Teres major action includes which of the following?

Teres major action includes which of the following?

• A. Abducts the arm
• B. Adducts and medially rotates the arm
• C. Laterally rotates the arm
• D. Flexes the arm

Answer: (B)

Teres major mainly brings the arm toward the body and rotates it inward at the shoulder. That combination—adduction plus medial rotation—fits its primary role, which is why this option is the best choice. It can also help extend the arm from a flexed position, acting alongside latissimus dorsi, but adduction with medial rotation are its hallmark actions. The other movements are done mainly by different muscles: abduction by the deltoid and supraspinatus, external (lateral) rotation by the infraspinatus and teres minor, and flexion by the pectoralis major (clavicular head) and anterior deltoid.

Teres major mainly brings the arm toward the body and rotates it inward at the shoulder. That combination—adduction plus medial rotation—fits its primary role, which is why this option is the best choice. It can also help extend the arm from a flexed position, acting alongside latissimus dorsi, but adduction with medial rotation are its hallmark actions. The other movements are done mainly by different muscles: abduction by the deltoid and supraspinatus, external (lateral) rotation by the infraspinatus and teres minor, and flexion by the pectoralis major (clavicular head) and anterior deltoid.