Swimmer’s shoulder is the most common swimming injury, with 80% of swimmers having experienced shoulder pain at some point in their careers. It is an overuse syndrome in which the athlete does not sustain a sudden, acute injury. Instead, inflammation builds up gradually, leading to a repetitive strain injury. There are two main causes:
A) Weakness in the muscles around the shoulder blade (rotator cuff), preventing them from stabilising the shoulder during overhead movements, which account for most movements in the water.
B) Poor swimming technique, which creates muscle imbalances between the left and right sides. This reduces the range of movement on one side and causes impingement between the acromion and the rotator cuff. For example, one of the most common mistakes swimmers make is breathing mainly to one side during front crawl.
Let’s look at the anatomy of the shoulder and ways to protect this area:
Anatomy of the shoulder joint
The shoulder joint is formed by three bones: the humerus, the scapula and the clavicle. The way these bones work together allows the head of the humerus to move in three dimensions within a hollow socket in the scapula, known as the glenoid, much like a ball rotating within a matching socket.
The head of the humerus (the ball) is held within the glenoid (the socket) largely through the action of four muscles. These muscles form a cuff around the head of the humerus and help it perform various movements, particularly internal and external rotation, hence the name ‘rotator cuff’.
The rotator cuff lies beneath the acromion, the uppermost part of the scapula. Between the acromion and the rotator cuff lies an important anatomical structure, the subacromial bursa. This sac contains a lubricating substance that is essential for joint lubrication and allows the upper arm to move freely, reducing friction and resistance between the bones.
When we raise our arm during everyday activities, the acromion comes into direct contact with the bursa and the rotator cuff. If this movement is performed repeatedly or against substantial resistance, the acromion can irritate the bursa, wear down the rotator cuff and, in some cases, create a hole in it. This is known as a rotator cuff tear.
Rotator cuff tears are often accompanied by damage to, or inflammation of, the bursa, which is also the main source of the patient’s pain.
Selective activation of the rotator cuff muscles. Whatever the diagnosis, whether impingement or instability, the athlete should perform exercises aimed at
activating the shoulder’s rotator muscles, which are very important for the stability of the entire shoulder girdle. It is worth emphasising that these are endurance muscles, so they should be activated using low resistance and high repetitions. Resistance should be increased very gradually to avoid recruiting neighbouring muscles. When neighbouring muscles assist with the movement, the exercise does not produce the intended results.