Which muscles are associated with horizontal abduction of the shoulder?

Which muscles are associated with horizontal abduction of the shoulder?

• A. Anterior deltoid, pectoralis major
• B. Posterior deltoid, infraspinatus, teres minor
• C. Middle deltoid, biceps brachii, supraspinatus
• D. Latissimus dorsi, teres major, triceps brachii

Answer: (B)

Horizontal abduction of the shoulder refers to the movement of the upper arm away from the midline of the body in a horizontal plane, particularly when the shoulder is positioned at approximately shoulder height. The prime movers involved in this action include the posterior deltoid, infraspinatus, and teres minor. The posterior deltoid is crucial for initiating horizontal abduction due to its location and function, as it helps extend and outwardly rotate the shoulder joint when the arm is lifted. The infraspinatus and teres minor, both part of the rotator cuff group, also contribute to this movement by externally rotating the humerus and assisting with the lateral stabilization of the shoulder joint during the horizontal abduction. Understanding these muscle functions is key for assessing and rehabilitating shoulder movements in various clinical settings. The other muscle groups listed are primarily involved in different shoulder movements, such as flexion, internal rotation, or adduction, thus not participating effectively in horizontal abduction.

Horizontal abduction of the shoulder refers to the movement of the upper arm away from the midline of the body in a horizontal plane, particularly when the shoulder is positioned at approximately shoulder height. The prime movers involved in this action include the posterior deltoid, infraspinatus, and teres minor.

The posterior deltoid is crucial for initiating horizontal abduction due to its location and function, as it helps extend and outwardly rotate the shoulder joint when the arm is lifted. The infraspinatus and teres minor, both part of the rotator cuff group, also contribute to this movement by externally rotating the humerus and assisting with the lateral stabilization of the shoulder joint during the horizontal abduction.

Understanding these muscle functions is key for assessing and rehabilitating shoulder movements in various clinical settings. The other muscle groups listed are primarily involved in different shoulder movements, such as flexion, internal rotation, or adduction, thus not participating effectively in horizontal abduction.