What is the Rotator Cuff?
The importance and relevance of the Rotator Cuff (RC) cannot be understated, as its proper function pertains to nearly every shoulder condition encountered by physical therapists. It comes up frequently in discussions amongst exercise enthusiasts and injured patients alike. Rarely a week that goes by that I am not asked, “What is the Rotator Cuff?”.
Unlike some other structures in the body, its name is not a clear indicator of its function.
The rotator cuff is a group of 4 muscles and tendons, originating on the shoulder blade (scapula), and attaching to the bone of the arm (humerus). Three of these muscles lie on the back side of the shoulder: Supraspinatus, infraspinatus, and teres Minor (all pictured below). The subscapularis is the lone muscle on the underside of the shoulder blade. In addition to controlling movements of the arm, the rotator cuff serves several other important functions such as firmly centering the humeral head in the shallow socket of the shoulder (see list below).
Functions of the Rotator Cuff:
1. Center the Head of the Humerus
2. Compress Head of the Humerus into the socket
3. Increase Tension to the Joint Capsule
4. Accelerate, rotate, and raise the Humerus
5. Decelerate Humeral Rotation (throwing)
The rotator cuff is the most frequently injured in patients who perform repetitive overhead activities in their jobs or sports. Injuries can range in severity from simple inflammation to full-thickness tears of one or more of the tendons. With physical therapy, many people can recover from rotator cuff dysfunction by improving shoulder mechanics, addressing muscular pain/spasm, teaching safe movement strategies, beginning a proper strengthening program, and working toward optimal posture.
Stay tuned for proper rotator cuff exercises in a future blog.
By Angelo Pompeo, PT, DPT