 The intrinsic muscles of the scapula include the muscles of the rotator cuff- the subscapularis, infraspinatus, teres minor and supraspinatus.These muscles attach to the surface of the scapula and are responsible for the internal and external rotation of the glenohumeral joint, along with humeral abduction.The extrinsic muscles include the biceps, triceps, and deltoid muscles and attach to the coracoid process and supraglenoid tubercle of the scapula, infraglenoid tubercle of the scapula, and spine of the scapula.