The Significance of the Subscapularis Muscle in the Pathogenesis of Recurrent Anterior Dislocation of the Shoulder

The pathogenesis of recurrent anterior dislocation of the shoulder has been studied at operation and by experiments on cadavers. 2. Lesions of the subscapularis muscle leading to lengthening and laxity have been demonstrated. 3. This lengthening is the prime factor in producing instability of the shoulder; capsular and bony defects are no more than subsidiary causes. 4. Good results have been obtained by a procedure based on this theory of etiology.