Group Fitness Instructor

Answer: A - The rotator cuff complex - comprised of the supraspinatus, infraspinatus, teres minor, and subscapularis muscles - has as its chief function the job of depressing the humeral “ball” down into the shallow “socket” (known as the glenoid fossa) of the shoulder joint. Without a sufficient rotator cuff, the shoulder girdle loses its capacity for normal kinematics. As the arm is elevated, the humerus rolls upward and rams into the underside of the acromion. This results in a greatly reduced ability to elevate the shoulder without hiking the entire shoulder complex.