When a swimmer complains of pain in the recovery phase of the freestyle stroke, Shoulder Impingement Syndrome is the most likely biomechanical cause.
The shoulder is configured as a ball and socket shaped joint that sits below the junction of the collar bone and the shoulder blade. The rotator cuff muscles are four small muscles that control how the ball of the humeral head moves within the shallow socket of the shoulder blade. The shoulder blade is stabilized on the chest wall by muscular control of upper back muscles like trapezius, rhomboids and serratus anterior. Without proper strength and coordination of the rotator cuff and shoulder blade stabilizer muscles, the humeral head can bump upwards into the bony arch of the shoulder blade that sits above it. With repetitive faulty movement, tendons of the rotator cuff can get pinched within this space, hence the term ‘impingement’ syndrome. Pain with arm reaching overhead and sleeping on the shoulder are common complaints with this condition.
Weakness of the rotator cuff, poor shoulder blade control, tightness of the shoulder joint, upper back stiffness and possibly too much shoulder mobility are all possible factors that can contribute to shoulder impingement. Stooped posture from desk and computer work often causes rotator cuff and upper back weaknesses that will contribute to shoulder impingement problems.
Soft tissues that can get inflamed with shoulder impingement are usually the supraspinatus or biceps tendon, the subacromial bursa and the acromioclavicular joint. Icing can help relieve the immediate symptoms after swimming, but the cause needs to be addressed to resolve the problem in the long term. Identifying weakness, inflexibility, hypermobility and/or shoulder blade control issues are critical in fixing this painful and dysfunctional injury. Appropriate exercise prescription is usually the treatment of choice, but tools like acupuncture, anti-inflammatory medication, manual mobilisation and massage techniques can be very helpful in accelerating recovery.
As Todd suggested, swimming is a very repetitive activity and faulty technique can often be the cause of shoulder pain during the freestyle stroke. Other training aspects to consider are sudden increases in volume, overuse of training paddles and lack of variety of stroke use during a swim session. Triathletes are often guilty of too much emphasis on front crawl. Even if you are not that proficient at backstroke or breast stroke, swimming a few lengths in warm up and cool down will help strengthen other shoulder girdle muscles and lessen the tendency for muscle imbalances to develop.
When a swimmer’s shoulder pain is not sorted out through the above noted actions, medical investigations such as x-rays, diagnostic ultrasound and MRI can be used to evaluate for rotator cuff tendon tears, ligament instabilities and arthritic changes.
(Originally published in No Limits Blog, February 2012)