The rotator cuff or the rotor cuff is a group of tendons and muscles around the shoulders that act to stabilize it. The rotator cuff is composed of four muscles of scapulohumeral origin. These muscles develop around the scapula and connect the humeral head, forming at the shoulder joint as a cuff. The rotator cuff functions to perform the following:
Assist in shoulder movement
Maintains the stability of the shoulder joint
Hold steadily the humerus
Compresses the shoulder joint (glenohumeral joint) during arm abduction to allow the deltoid muscle to elevate the arm
Without the presence of the rotator cuff, the humeral head will go out from the glenoid fossa during movements of the arm. The humeral head fits on the glenoid fossa forming somewhat a golf ball placed on a golf tee. The compression of the glenohumeral joint is known as concavity compression, which prevents the head of the humerus from getting out of the shallow glenoid fossa during movements.
The rotator cuff comprises of four muscles with their tendons. These muscles are innervated by the nerves originating from the C5 to C6 vertebrae. These include:
Supraspinatus Muscle- Responsible for arm abduction
Infraspinatus Muscle- Responsible for externally rotating the arm
Teres minor Muscle- also responsible for rotating the arm externally
Subscapularis Muscle- responsible for the internal rotation of the humerus
The rotator cuff is also prone to injuries. The tendons may become torn due to trauma to the shoulder or by wear and tear mechanisms. The torn rotator cuff may lead to pain and arm movement restriction. This type of injury is common to baseball pitchers, foot ball players, cheerleader, volleyball players, swimmers and other individuals who make repetitive throws, swinging, or overhead arm movements. Another injury to the rotator cuff in is the form of impingement.
Any injury to the rotator cuff should be managed promptly because this may lead to movement restrictions. Proper management of the rotator cuff should also be instituted to prevent injuries in the area. Some of these preventive measures aid in strengthening the rotator cuff. These include:
Proper posture – Maintain a good posture by preventing dropping of the shoulders because this may overstretch the muscles that support the shoulders.
Proper sleeping positions – Avoid sleeping positions that involve overhead extension of the arm to prevent circulatory compromise to the area. This position also leads to muscle strain during the prolonged hours of sleep.
Perform strengthening exercises – These exercises promote flexibility and strength of the muscles in the rotator cuff to maximize arm movement and prevent injuries. Injuries are prevented by balancing internal rotations to external rotations of the shoulder joint. Exercising the rotator cuff yields better posture because of avoiding tightness on the internal rotators. Examples of these exercises are the side-lying external rotation and propped external rotation exercises. The former is done by lying on the side and placing the arms close to the body in a 90 degree angle flexion at the elbows. Gradually externally rotate the arm (with a dumbbell) so that the dumbbell is placed towards the ceiling. The propped external rotation is done by sitting parallel to the side of the table with the forearm placed on top of the surface in a 90 degree angle at the elbow. Grasp the dumbbell on the surface and lift it until the forearm is pointed upwards. Repeat the routine for the other arm.
Rest – Rest is essential to those who perform repetitive overhead motions of the arm to prevent strain injuries and allow the muscles to relax.
The rotator cuff is an essential structure in the shoulder responsible for arm and shoulder movements which needs proper care to prevent injuries. However, when those injuries or pain become a problem, Dr. Mohr, your Tampa chiropractor, is here and ready to help.