Shoulder pain is one of the more common injuries in tennis players, affecting both young and old alike. The general reason is fairly simple: By design, the shoulder is not meant to perform such forceful, and often overhead, movements. Include the tremendous amounts of repetition inherent in the game, and you have all the key components of an injury waiting to happen.
Cheer up fellow tennis players. I’m not suggesting that we lay down our rackets … at least not without a fight! The most obvious solution to this problem is to try to affect the shoulder directly by using methods to strengthen or increase the flexibility of the shoulder. The rotator cuff, the group of muscles deep within the shoulder, does a lot of work for us when we’re trying to smash a forehand by our opponent. It’s only fair that we return the favor and make sure that it’s just as healthy as our own game. While focusing our attention on the shoulder itself is very important, it’s only part of the equation. Our body’s foundation is the other major component and is frequently overlooked when dealing with shoulder pain.
Our foundation is comprised of both our leg and core (trunk) muscles. Believe it or not, our foundation is where a lot of our power comes from. Some estimates say at least 50 percent of our power comes from our core. Most people think that arm or shoulder strength is what makes you hit the ball hard—that’s why when people want to hit a ball harder, they swing harder.
Using common sense, we can see that our foundation is more responsible for ball speed. First off, compare the size of your leg muscles and your shoulder muscles. Your leg muscles are obviously much bigger and more powerful. From a practical standpoint, compare how hard you hit a ball moving forward and using your legs to drive through the ball, as opposed to when you’re scrambling backwards and have to “muscle” the ball without any forward momentum.
As you prepare to hit a ball, force is generated in your legs and core and transferred through your mid-section and trunk. The force continues through the shoulder, which adds its own amount of force, traveling down the arm and through the racket as it impacts the ball. In reality, the shoulder is more responsible for transferring and directing the force being received from your foundation than attempting to generate all the force itself.
What happens when our foundation doesn’t provide the needed force? The answer is that the shoulder will try to compensate for it by adding more of its own force. Here’s the problem: For your shoulder to make up for a 20 percent loss in force due to a weak foundation, it would have to increase its speed of swing by almost 40 percent. That’s hard work on the shoulder! Repeatedly having the shoulder try to compensate for a weak foundation can lead to rotator cuff strain or tendonitis, as well as impingement. That’s why a strong foundation is so important to your shoulder’s health.
Do you have a weak foundation? Here’s a quick way to check. Perform a one-legged squat. If you note balance problems or if your knee wobbles and falls inward towards your midline, then chances are you need to strengthen your foundation. Every player can benefit from a stronger foundation. Not only can it keep your shoulder healthy, but it can increase your power and improve your court coverage! If you’re experiencing shoulder pain, a thorough evaluation by your physical therapist can help determine whether your problem is related to faulty shoulder mechanics or if the shoulder is overworked due to a weak foundation.