Which chest muscle adducts the arm, medially rotates it, and draws it forward?

• A. Latissimus Dorsi
• B. Pectoralis Major
• C. Deltoid
• D. Teres Major

Answer: (B)

The action described—adducting the arm, medially rotating it, and drawing it forward—fits the chest muscle known as the pectoralis major. This large chest muscle pulls the humerus toward the midline of the body (adduction), turns the arm inward (medial rotation), and, especially from the extended position, flexes the shoulder to bring the arm forward. Its two heads work together: the clavicular portion helps flex the arm (draw it forward), while the sternocostal portion contributes to adduction and medial rotation.

Latissimus dorsi mainly extends the arm and pulls it back and down (adduction and medial rotation, but toward the back, not forward). The deltoid primarily abducts the arm, with anterior fibers aiding flexion and medial rotation but not the primary adduction or forward draw. Teres major assists with adduction and medial rotation and can extend the arm, but it doesn’t draw the arm forward in the same way the pectoralis major does.