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

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

Answer: (B)

The chest muscle that fits all three actions—adducting the arm toward the midline, medially rotating the shoulder, and drawing the arm forward across the chest—is the pectoralis major. This large chest muscle has two parts: the clavicular part helps flex the arm (draws it forward) and adducts it, while the sternocostal part mainly adducts and medially rotates the humerus.

Other muscles listed also adduct and medially rotate, but their primary effect is different: latissimus dorsi and teres major tend to pull the arm downward and backward (extension and inward rotation) rather than forward across the chest. Coracobrachialis assists with flexion and adduction but doesn’t draw the arm forward across the chest as the pectoralis major does.