Rotator cuff stability vary according to their stiffness and the direction of the force they apply upon the joint. In addition to stabilizing the glenohumeral joint and controlling humeral head translation, the rotator cuff muscles also perform multiple functions, including abduction, internal rotation, and external rotation of the shoulder. The infraspinatus and subscapularis have significant roles in scapular plane shoulder abduction (scaption), generating forces that are two to three times greater than the force produced by the supraspinatus muscle. However, the supraspinatus is more effective for general shoulder abduction because of its moment arm. The anterior portion of the supraspinatus tendon is
Rotator cuff tear the rotator cuff muscles become irritated and inflamed while passing through the subacromial space beneath the acromion. This relatively small space becomes even smaller when the arm is raised in a forward or upward position. Repetitive impingement can inflame the tendons and bursa, resulting in the syndrome. Well-documented anatomical factors include the morphologic characteristics of the acromion. Hooked, curved, and laterally sloping acromia are strongly associated with cuff tears and may cause tractional damage to the tendon. Conversely, flat acromia may have an insignificant involvement in cuff disease and consequently may be best treated conservatively. The development of these different