The effect of shoulder muscle training in patients with recurrent shoulder dislocations.

Thirty-three shoulders in 29 patients with recurrent shoulder dislocations, of both traumatic and nontraumatic type, have been studied. The patients suffered from muscle weakness, and had also a hypotrophy of the supra- and infraspinatus muscles. A special training program using an isokinetic pulley-weight apparatus, for muscle strength, coordination and endurance training of the rotator-cuff muscles and the deltoid were given all patients. Shoulder flexors, internal and external rotator muscles were trained three times a week, during a period of 8 weeks. At follow-up one year after completion of the specific training program all shoulders except five were improved. Five shoulders had remaining instability. Four of these patients had generalized joint laxity and a much decreased humeral head retroversion, and were later on stabilized with a rotational osteotomy of the proximal humerus. One of the shoulders with remaining instability was of traumatic type with normal skeletal anatomy. This patient was later on stabilized with a Putti-Platt procedure. We conclude that most of the patients were relieved from pain, and had decrease or cessation of their dislocations. Factors indicating a less good result of training were an abnormal skeletal anatomy, and/or a multidirectional type of instability.