Rotator cuff tear Because individuals are highly dependent on the shoulder for many activities, overuse of the muscles can lead to tears, the vast majority again occurring in the supraspinatus tendon. The role of the supraspinatus is to resist downward motion. The supraspinatus resists downward motion while the shoulder is relaxed as well as when carrying weight. Such a tear usually occurs at its point of insertion onto the humeral head at the greater tubercle. Even though the supraspinatus is the most commonly injured muscle of the four muscles in the rotator cuff, the other three muscles that comprise the rotator cuff, the
Rotator cuff tear single physical examination test distinguishes reliably between bursitis, partial-thickness, and full-thickness tears. On the contrary, a combination of tests seems to provide the most accurate diagnosis. For impingement, these tests include the Hawkins-Kennedy impingement sign in which the examiner medially rotates the patient's flexed arm, forcing the supraspinatus tendon against the coracoacromial ligament and so producing pain if the test is positive a positive painful arc sign, and weakness in external rotation with the arm at the side. For the diagnosis of full-thickness rotator cuff tear, the best combination appears to include once more the painful arc and weakness in