A 19-year-old man is brought to the emergency depament after dislocating his shoulder while playing soccer. Following reduction of the dislocation, he has pain over the dorsal region of the shoulder and cannot abduct the arm normally. An MRI of the shoulder shows a torn muscle. Which of the following muscles is most likely to have been damaged by this injury?

Supraspinatus is one of the rotator cuff muscles. Its tendon is relatively avascular and is often injured when the shoulder is dislocated. This muscle initiates abduction of the arm, and damage would impair this movement. Muscle Movement Supraspinatus abduction of the arm coracobrachialis adduction and flexion of the arm triceps extend the elbow pectoralis minor accessory respiratory muscle and to stabilize the scapula