A 22-year-old male is thrown through a plate glass wall in a fight. Radiologic examination reveals that the lateral border of his right scapula is shattered. He is admitted to the emergency department, and physical examination reveals difficulty laterally rotating his arm. Which of the following muscles is most probably injured?

Infraspinatus is responsible for lateral rotation (along with the teres minor, not a choice here). Teres major is responsible for adduction and medial rotation of the humerus. Latissimus dorsi is responsible for adduction, extension, and medial rotation of the humerus. Trapezius is an elevator of the scapula and rotates the scapula during abduction of the humerus above the horizontal plane. Supraspinatus is responsible for the 0deg to 15deg of abduction.