What is the rotator cuff?
Shoulders consist of a ball and socket, two bone structures that are not completely congruent with each other – think a basketball trying to articulate with a dinner plate. That’s why the rotator cuff is required. These muscles are designed to pull the ball in and keep it pressed against the socket. They get their name as the muscles contribute to rotation of the arm and the tendon forms a cuff around the ball holding it into the socket. These muscles act as stabilisers, primarily helping to hold the ball in the socket rather than generating movement. This joint does not have the stability of hips, where the socket is deeper and the balls fits inside better.
Rotator cuff injuries
Injury to the rotator cuff can come in a variety of forms. Tendon degeneration and tear, either acutely or slowly over time, is often seen in older age groups. Impingement of cuff tendons is also common. This occurs when the function of the cuff muscles deteriorates and allows the ball to move upwards and squash the tendon into the top of the socket.
Why are rotator cuff injuries common in tennis?
From hitting with tremendous power to fine touch, tennis places incredible demands on the shoulder. It requires extreme movement and repetition – which can cause a degree of imbalance among rotator cuff muscles. This reduces their ability to work effectively together. As rotator cuff muscles are involved in every movement they need adequate strength, endurance and co-ordination to provide the required support.
Another consequence of the repetitive nature of tennis strokes is the effect this has on other structures supporting the shoulder, like the ligaments. These gradually stretch over time, for example when the arm winds up to serve, heavy strain is placed on the ligaments at the front of the joint. If these ligaments stretch then a greater demand is transferred to the rotator cuff to overcome this reduced support.
This largely depends on the degree of the damage to the rotator cuff. A significant tear may require surgery to repair, which could result in up to six to nine months off court. Recovery is much quicker for a minor tear, which typically needs between four to six weeks. It is important that the shoulder and rotator cuff is at full strength before returning to full competitive training and play to prevent further damage.
Recovery times for impingements also varies, if muscle imbalance is not considerable it can heal in one to two weeks. More extreme cases may take up to three months. Training can usually be resumed earlier, starting with pain free ground strokes and as the condition improves gradually working back towards overhead shots.
A common mistake is not focusing on maintaining the balance between the rotator cuff muscles and having too much emphasis on attempting to increase power and strength. Rotator cuff muscles are actually quite small and work at a lower intensity for longer periods of time, therefore need to be trained in a different manner to emphasise this endurance. As tennis strokes tend to have a bias towards the internal rotation motion, there is a need to pay more attention to the external rotation element of the cuff muscles. A good test is to stand with both elbows bent at 90 degrees and have a friend resist you pushing your wrists out laterally apart from each other, if there is a significant difference between the sides or they both collapse easily, then there is a weakness that needs to be addressed.