What is the Rotator Cuff?

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ROTATOR CUFF MUSCLES are essential in shoulder stability and function. 50% of all patients who visit doctors or orthopaedic surgeons for shoulder pain are due to ROTATOR CUFF issues.

The ROTATOR CUFF is a group of four muscles, one from the front, three from the back. They work in unison to maintain the proper relationship of the two bones of the shoulder joint – the humeral head and the glenoid during movements of the shoulder. Seventeen muscles are involved in shoulder motion. Only four, the ROTATOR CUFF MUSCLES, compress the humeral head against the glenoid in order to maintain a smooth rolling motion of the humeral head on the glenoid surface during all movements of the shoulder.

Lack of ROTATOR CUFF strength to counteract the upward motion of the humeral head during shoulder elevation leads to ROTATOR CUFF TENDON impingement against the under surface of the bone on top. This leads to frictional tears on top of the tendon as it rubs against under surface of the bone, or tensile failure tears on the undersurface of the tendon as the tendon is pulled by the upward motion of the shoulder. Similar pathology occurs with overhead throwing activity where the anterior displacing force is not balanced by posterior ROTATOR CUFF strength, leading to posterior tensile overload tears. Bench pressing load and injure the posterior shoulder joint when the anterior ROTATOR CUFF is not able to maintain the central location of the humeral head on the glenoid as the weight pushes the shoulder out the back.

Maintenance of the strength of the ROTATOR CUFF will help prevent shoulder injury due to a weakened ROTATOR CUFF.