Sports that require overhead movement and excessive throwing may cause pain in the shoulder. Throwing may gradually become more painful, if not impossible. In repetitive throws, the anterior capsule may stretch in the cocking and early acceleration phase of the throw. This leads to excessive external rotation.
At the end of the throw, the posterior capsule may suffer small tears leading to scarring and thickening of the posterior capsule. This leads to the limitation and stiffness of internal rotation.
The loose anterior capsule allows the head of the humerus to rotate too much at the cocking phase of the throw. The head of humerus then grinds on the upper part of the postero-superior labrum and posterior part of the supraspinaus tendon. This imbalanced hyperlaxity leads to fraying of the posterior labrum and supraspinatus tendon, which induces pain. This condition is also called internal impingement.
Treatment
Conservative treatment should always be preferred: muscle strengthening and balance stretching of the dorsal capsule. In severe cases, especially in conjunction with anterior instability, operative treatment may be necessary. It depends a lot on the case. Operative treatment may include attachment of the dorsal labrum and/or plication of the joint capsule and release of the dorsal capsule. Decision-making in the procedure is never straight forward and care must be taken not to tighten the joint too much. For this reason conservative treatment is preferred. The conservative and operative treatments always involve a break in throwing depending on the severity of the problem. After operative treatment, the break is several months.
Postoperative treatment
In my practice, the patient wears a sling for four weeks and is permitted to do light movements at the waistline. The patient can write, use a computer, make coffee, eat, etc. However, the patient must be extremely careful not to harm the reconstruction. The sling is removed after 4 weeks and active rehabilitation, which emphasizes muscle exercise and balancing, may begin. Taking care not to stretch the anterior joint capsule too soon is crucial. The patient is permitted to engage in heavy labor 4 months and sports 6–12 months after surgery. Rehabilitation should never be too hasty.
Once the range of motion is at a reasonable level, concentrating on muscle balancing and exercises is crucial; in some respects, returning to the original conservative treatment plan to achieve sustainable results.