Which muscles facilitate shoulder abduction?

Shoulder abduction is primarily facilitated by the middle deltoid and the supraspinatus muscles. The middle deltoid is a key muscle located on the outer part of the shoulder, and its fibers are oriented to pull the arm away from the body during abduction. The supraspinatus, one of the rotator cuff muscles, assists the initial phase of abduction, first 15 degrees before the middle deltoid takes over. This combination of the middle deltoid and supraspinatus makes them the primary movers in this action.

While other muscles mentioned, such as the anterior deltoid, the latissimus dorsi, or the pectoralis major, may play roles in shoulder movements, they are not the main facilitators of shoulder abduction. The anterior deltoid primarily contributes to shoulder flexion and is not focused on abduction. The latissimus dorsi and pectoralis major are more involved in shoulder adduction and internal rotation of the arm rather than abduction. Therefore, the middle deltoid and supraspinatus are the correct choices that directly facilitate shoulder abduction.