Rotator cuff tear results from tear of one or more of the rotator cuff muscles and their associated tendons. Which is the most commonly injured rotator cuff muscle?

Supraspinatus is the most frequently injured muscle or tendon. Most of the injury result from overuse. Supraspinatus muscle: Its primary action is humeral abduction. The suprascapular nerve (C5-C6) and the suprascapular aery provide its innervation and blood supply.Infraspinatus muscle: Its primary action is lateral rotation of the humerus. The suprascapular nerve and the suprascapular aery provide its innervation and blood supply.Teres minor muscle: It causes lateral rotation of the humerus. The axillary nerve and circumflex scapular aery provide its innervation and blood supply.Subscapularis muscle: Causes medial rotation of the humerus with contraction. Upper and lower subscapular nerves and suprascapular, axillary, and subscapular aeries provide its innervation and blood supply.