Recreational tennis has often fallen behind many other sports in its physical preparation, sport-specific fitness, and injury prevention. Due to the high technical levels of skill required, many recreational and sub-elite programs focus the vast majority of their time on developing the correct technique and hitting the thousands of balls needed to make those changes permanent.
It is only when things start to go wrong do we consider that we may need to look at the dark side of the sport: physical preparation and injury prevention. At the elite level, the most frequently injured parts of the body are within the lower limb due to the increased athletic demands of the modern game. Rapid acceleration and deceleration over two to five hours of practice or play can stress the lower extremities and accounts for 39-51% of all injuries (Kibler and Safin). Lower extremity injuries provide the most time absent at the top level. As you move down through the tiers of the tennis system, injury bias tends to shift. A more significant proportion of injuries occurs in the upper extremities with the shoulder accounting for around 2.6-3.6 injuries per 1000 hours of exposure at sub elite level (Gescheit, et al). The good news is there are many effective things we can do to protect the shoulder over the long recreational tennis career.
Firstly, let’s cover the technical side. A tennis stroke should be played as a ‘kinetic chain of motion.’ This starts with the feet pushing off the court, transitioning body weight forward before carrying that force through the trunk, causing good trunk rotation before the arm does its thing. We know from extensive studies, particularly in baseball, that if part of the kinetic chain is not functioning properly (for example you are not transferring body weight forward using your legs), the arm compensates and swings extra hard to generate that missing power. If not corrected, this missing link in the chain can overload the smaller muscles of the shoulder and be the start of the grumbling shoulder. Kibler and Chandler calculated that a 20% decrease in kinetic energy delivered from the hip and trunk to the arm requires a 34% increase in the rotational velocity of the shoulder to impart the same amount of force to the hand.
The other major issue with the tennis swing is, in simplistic terms, that everything is a push! Each swing requires a rapid acceleration in the forward direction and then requires muscles at the back of the shoulder to rapidly apply the brakes at the end of the swing. Ultimately this leads to imbalances in the shoulder, and if the tipping point is reached, it can mean a trip to your physical therapist.
So what can you do to minimize injury best? Foremost, consider technique and the kinetic chain. There are many case studies of tennis and baseball players resolving their shoulder pain by strengthening a weaker lower extremity or focusing on rotational core strength; everything except the shoulder. The more you can get the power muscles of the trunk and legs involved in your stroke, the more the upper limb is protected. Simply watch the pros take off and rotate from the ground as they hit their groundstrokes. Secondly, you need some pull to your push! It could be worth considering some strengthening exercises where you pull the weight towards you (the opposite direction of a tennis stroke) to keep the shoulder balanced. Many players will even go as far as doing some overhead backward throws to balance the overhead pushing forces of their games.
If you have undiagnosed shoulder pain, please make sure you get it looked at by a trained professional. I hope this gives you something to consider as tennis is a game for life if you can get and keep your shoulders strong, stretched, and stable.