| By Dr. Charles Ruotolo

For most tennis players, the most feared injury is usually tennis elbow, as this was traditionally the most common. However, with more modern training and swing adaptations, the frequency of this injury is shrinking. Yet, one of the more under-recognized injuries among players is a shoulder injury. 

Tennis is a game of repetition, where players are running side to side, while using power generated in their core which is funneled and magnified through the shoulder blade and into the shoulder and the arm to return each shot or serve. In fact, 50-60 percent of the energy of each shot or serve comes from the lower extremities and the body’s core. This then needs the correct biomechanical function of the shoulder blade to funnel this energy into the upper extremity and to the racquet and eventually the ball. The muscles of the shoulder blade, including the upper, middle, and lower trapezius and the serratus muscles are very important to retract, stabilize and rotate the scapula (shoulder blade) to facilitate proper shoulder function and strength. The rotator cuff consists of four muscles and tendons that attach at the shoulder together with a “ball in socket” function. The forward, side to side, internal and external rotation of the shoulder area are all controlled by the rotator cuff and the muscles of the shoulder blade. Fatigue and loss of neuromuscular control of these muscles is common with repetitive overuse which can cause altered biomechanics, loss of performance and ultimately shoulder injuries, including injuries to the labrum (the cartilage that lines the outside of the shoulder socket) and the rotator cuff. For these reasons, tennis players are considered "overhand athletes," and often suffer from the same types of injuries as often seen in baseball players and quarterbacks.

As a young athlete, repetitive stress on the shoulder initially causes two significant problems which can cause pain and decrease performance. First is scapular dyskinesis, or altered muscular control of the shoulder blade. The shoulder blade needs to retract as a racquet is brought into the overhead cocking phase of a serve or shot. Then these same muscles must control the shoulder blade as the racquet is swung through into the deceleration phase of a serve which occurs in a fraction of a second. This pulls the shoulder blade forward which then needs to be retracted again for the next shot or serve. With repetitive stress, the shoulder blade might sit in a protracted (or more forward position) and usually lower than the other shoulder. This then leads to loss of muscular control and abnormal movement of the shoulder blade with the overhead swing of serving.

The second problem that arises is tightness of the posterior capsule (tightness of the tissue that forms the back of the shoulder joint) which is also most likely from the repetitive stress of the decelerating arm.  This is called “glenohumeral internal rotation deficit” or GIRD. With repetitive stress on the back of the shoulder capsule the capsule thickens and the athlete loses internal rotation of the shoulder. This can affect the way the shoulder rotates and can cause superior labrum tears or tears of the cartilage at the top of the shoulder socket where the biceps tendon attaches. Typically, scapular dyskinesis and GIRD cause pain, but a superior labral tear usually will cause a tennis player to have a significant drop in performance if they are able to play at all. In fact, a recent study showed that 25 percent of players between the ages of 12-19 reported having shoulder pain usually from dyskinesis and GIRD.

Perhaps even more concerning is that 50 percent of middle-aged players reported having shoulder pain, but not entirely from dyskinesis and GIRD. For the athletes over the age of 35, repetitive overuse can injure and fray the tendons of the rotator cuff. This is most likely from repetitive stretch on these tendons in the deceleration phase of swinging a racquet and is exacerbated by altered mechanics of the shoulder blade. These injuries increase with age and complete tears of the rotator cuff become more common every decade over the age of 50. So, while younger players have altered biomechanics of the shoulder blade (scapular dyskinesis) and stiffness of the back of their shoulder capsule (GIRD) and might even develop tears of their superior labrum, players over the age of 35 also have to deal with fraying and tearing of their rotator cuff.

The most important way of preventing these problems is stretching and focused muscle strengthening. Posterior capsular stretching (stretching the back of the shoulder) has been shown to be successful in limiting loss of shoulder internal rotation and has also been shown to decrease the injury rate in overhand athletes. Focused strengthening of the muscles of the shoulder blade and the rotator cuff can help maintain correct biomechanics and keeps the tennis player at their highest level of play.

Some tips that professionals and casual players alike can follow:

►Always stretch before and after competition. Posterior shoulder stretching or the “sleeper stretch” is an important part of this routine.

►Receive professional coaching to ensure a mechanically sound serve and hitting motion.

►Do not start off serving fast out of the gate. Start at 50 percent and allow blood flow to increase and then gradually speed up.

►Avoid tossing the ball too high or in one direction. Having to lean one way or reach too high puts unnecessary stress on the rotator cuff.

►If you have shoulder pain during play, do not push it under any circumstance. However, that does not mean to keep your shoulder completely immobile. Rather, keep the shoulder mobile to maintain blood flow and avoid stiffness.

►If you tend to feel soreness after competition, be sure to ice the shoulder the same way a pitcher in baseball would.

►If you are an avid tennis player, spend time strengthening your rotator cuff in addition to your normal regimen. It will not only help you avoid injury, but add a few miles per hour to your serve as well.

Dr. Charles Ruotolo

<p>Dr. Charles Ruotolo is a Board-Certified Orthopedic Surgeon and the founder of Total Orthopedics and Sports Medicine with locations in Massapequa, East Meadow and the Bronx, N.Y. Dr. Ruotolo completed his orthopedic residency program at SUNY Stony Brook in 2000. After his residency, he underwent fellowship training in sports medicine and shoulder surgery at the prestigious Sports Clinic of Laguna Hills, Calif. He is also a fellow of the American Academy of Orthopedic Surgeons. As an Associate Master Instructor of Arthroscopy for the Arthroscopy Association of North America, Dr. Ruotolo actively teaches other orthopedic surgeons advanced arthroscopic skills in shoulder surgery. As an avid researcher he has also published multiple articles on shoulder injuries and shoulder surgery in the peer review journals of Arthroscopic Surgery and of Shoulder and Elbow Surgery. For more information, visit <a href="http://www.totalorthosportsmed.com" onclick="window.open(this.href, 'wwwtotalorthosportsmedcom', 'resizable=no,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no'); return false;">www.totalorthosportsmed.com</a>.</p>