Swimming is an endurance sport but “swimmer’s shoulder”, a broad non-medical term often used to describe a variety of shoulder injuries, can affect swimmers at all levels. Elite and competitive swimmers log up to 80,000 metres weekly, which places significant stress on their shoulder joints.
The upper body provides 90% of the propulsive force to move through water. Due to the amount of force generated and the range of motion required to swim efficiently, the shoulder needs to have perfect mechanics.
According to the Journal of the American Academy of Orthopaedic Surgeons, many shoulder injuries are preventable with proper technique, training, stretching and strengthening. Shoulder pain affects up to 91% of competitive swimmers.
With fatigue the pectoralis compensate for tired muscles, which can cause the peak of the shoulder blade to rub (impinge) against the rotator cuff (tendon and bursa), stress the anterior (front of the body) ligaments, and create tears in the tissue that holds the top of the arm bone in place.
Intense, repetitive rotation of the shoulder blade over the chest wall can overstretch and loosen the upper back muscles that keep the shoulder bones in position.
Gleno-humeral internal rotation deficit is caused by intense, repetitive rotation of the shoulder blade. The front shoulder ligaments overstretch and loosen, causing soft tissues and muscles in the back to tighten to compensate for the loosened front shoulder muscles.