Which actions are associated with the teres major?

• A. Adduction, internal rotation, and extension
• B. Abduction, external rotation
• C. Flexion and horizontal adduction
• D. Depression of the scapula

Answer: (D)

Teres major moves the arm at the shoulder in three main ways: it adducts the humerus (brings the arm toward the body), it internally rotates the humerus, and it extends the arm from a flexed position. Its pull on the humerus is directed toward the trunk and downward, which fits those three actions together. It does not depress the scapula; that scapular motion is produced by other muscles such as the lower fibers of the trapezius and the pectoralis minor. So the combination of adduction, internal rotation, and extension best describes the teres major.