Shoulder horizontal adduction is mainly performed by which muscles?

Shoulder horizontal adduction is mainly performed by which muscles?

• A. Pectoralis major.
• B. Anterior deltoid.
• C. Pectoralis major and anterior deltoid.
• D. Deltoid and pectoralis major.

Answer: (C)

Horizontal adduction of the shoulder means moving the arm across the front of the body in the horizontal plane. The main muscles that produce this movement are the pectoralis major and the anterior portion of the deltoid. The pectoralis major, especially the sternocostal portion, pulls the arm toward the midline across the chest, providing strong adduction. The anterior deltoid helps by flexing and guiding the arm across when it’s raised to shoulder height, adding a crucial assisting component. Together, they account for the bulk of the horizontal adduction action. The other motions and muscles tend to move the arm in different directions (such as horizontal abduction or extension), so they don’t contribute as much to this specific movement.

Horizontal adduction of the shoulder means moving the arm across the front of the body in the horizontal plane. The main muscles that produce this movement are the pectoralis major and the anterior portion of the deltoid. The pectoralis major, especially the sternocostal portion, pulls the arm toward the midline across the chest, providing strong adduction. The anterior deltoid helps by flexing and guiding the arm across when it’s raised to shoulder height, adding a crucial assisting component. Together, they account for the bulk of the horizontal adduction action. The other motions and muscles tend to move the arm in different directions (such as horizontal abduction or extension), so they don’t contribute as much to this specific movement.