Which muscles are involved in shoulder adduction?

Shoulder adduction involves bringing the arm closer to the midline of the body. The muscles that primarily facilitate this movement include the latissimus dorsi, teres major, and pectoralis major.

The latissimus dorsi is a large muscle of the back that not only contributes to adduction but also assists in extension and medial rotation of the shoulder. Teres major, often considered a synergist to the latissimus dorsi, also aids in adducting the arm and helps in medial rotation. Pectoralis major, a large chest muscle, plays a vital role in both adduction and flexion of the shoulder.

These three muscles work together effectively to accomplish shoulder adduction, making the selected answer the correct choice for this movement.

In contrasting this with other muscle groupings, the other options contain muscles that do not predominantly function in shoulder adduction or are primarily involved in different movements, such as abduction or stabilization. For example, muscles like the supraspinatus are mainly involved in shoulder abduction, while the anterior deltoid is more active in flexion and internal rotation than in adduction. Thus, recognizing the specific roles of these muscles in shoulder mechanics is essential for understanding their function during