ROLE OF THE ROTATOR CUFF
Mimi Zumwalt, MD

The shoulder is one of the more complex joints in our body. Not only does it help to position the hand in space for various functions, it also has a tremendous range of motion. Because of the latter, it tends to lack inherent bony stability (analogy of a golf ball sitting on a tee). As a consequence, the shoulder joint relies on soft tissues, ie ligaments and tendons along with other structures, to effectively deepen and keep "the ball seated in the socket" (humeral head centered in the glenoid).

Of utmost importance in stabilizing the shoulder are the rotator cuff muscles, three on the back of the scapula (shoulder blade), and one on the front, to help the joint stay in balance upon muscular contraction. However, the rotator cuff does not work alone, other surrounding muscles also play a role in centralizing the humeral head. These include the deltoid, long head of the biceps, and some of the upper back muscles such as the rhomboids and others.

In throwing athletes or those using their shoulders for overhead activities, certain structures become tight and others get stretched out from the repetitive nature of the overhead motions. As a result, in order for the "ball" to stay in the "socket", the rotator cuff has to work a little harder to overcome the "looseness" or laxity of the shoulder joint. As a consequence, these muscles/tendons become overused and get worn out, similar to a frayed rope over a pulley, or holes in jeans at the knees and jackets at the elbows.

Indeed, the dynamic nature of the shoulder/girdle (shoulder blade & clavicle/collar bone) musculature along with static restraints of attached soft tissues is the key to preventing overuse injuries of this important joint. However, these musculotendinous complexes need to "stay in shape" - maintain their condition/ strength in order to maximize their potential to support the bones making up the shoulder/ girdle.

This is where rehabilitation exercises come in. This conditioning program encompasses much more than just "pushing" a few weights around in the gym. Not only do the shoulder/girdle muscles need to be strengthened, the chest, arm, and back muscles have to be addressed as well. Specifically targeting each muscle group by resistive training will help to fill in any deficits from previous trauma suffered or injuries incurred from "wear and tear" as a natural process of aging.

More importantly, it is usually better trying to prevent rather than treat an injury to the shoulder once it occurs. Seeking advice from a licensed physical therapist and/or athletic trainer specializing in biomechanics and kinesiology prior to instituting any type of rehab program would be quite helpful. It is convenient to have a gym/facility with various weight lifting equipment to facilitate performance of appropriate exercises. If this is unavailable or impractical, different dumbbells or varied resistance rubber bands can be used for the same purpose.