The scapula plays an important role in<unk> . It is a wide, flat bone lying on the posterior thoracic wall that provides an attachment for three different groups of muscles. 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. These muscles are responsible for several actions of the glenohumeral joint. The third group, which is mainly responsible for stabilization and rotation of the scapula, consists of the trapezius, serratus anterior, levator scapulae, and rhomboid muscles and attach to the medial, superior, and inferior borders of the scapula. Each of these muscles has its own role in shoulder function and must be in balance with the others in order to avoid shoulder pathology. Abnormal scapular function is called scapular dyskinesis. One action the scapula performs during a throwing or serving motion is elevation of the acromion process in order to avoid<unk>  of the rotator cuff tendons. If the scapula fails to properly elevate the acromion,<unk>  may occur during the cocking and acceleration phase of an overhead activity. The two muscles most commonly inhibited during this first part of an overhead motion are the serratus anterior and the lower trapezius. These two muscles act as a force couple within the glenohumeral joint to properly elevate the acromion process, and if a muscle imbalance exists, shoulder<unk>  may develop. The scapula may also be misplaced if a rib deep to it is not moving correctly. Often in the case of<unk> , the scapula may be anteverted such that the shoulder on the affected side appears protracted. The ribs that may cause such an anteversion of the scapula include ribs 2–8.
Shoulder impingement syndrome
Rotator cuff tear
Facet syndrome
Snapping hip syndrome
Epicondylitis
Patellar subluxation syndrome
Patellofemoral pain syndrome
Milwaukee shoulder syndrome