The "rotator cuff" muscle includes all except-
Ans. C. Teres majorROTATOR CUFF MUSCLESFour of the scapulohumeral muscles (intrinsic shoulder muscles)--supraspinatus, infraspinatus, teres minor, and sub scapularis the SITS muscles)--are called rotator cuff muscles because they form a musculotendinous rotator cuff around the glenohumeral joint. All except the supraspinatus are rotators of the humerus; the supraspinatus, besides being part of the rotator cuff, initiates and assists the deltoid in the first 15deg of abduction of the arm. The tendons of the SITS muscles blend with and reinforce the fibrous layer of the joint capsule of the glenohumeral joint, thus forming the rotator cuff that protects the joint and gives it stability. The tonic contraction of the contributing muscles holds the relatively large head of the humerus in the small, shallow glenoid cavity of the scapula during arm movements.a. Supraspinatus. The supraspinatus occupies the supraspinous fossa of the scapula. A bursa separates it from the lateral quarter of the fossa. To test the supraspinatus, abduction of the arm is attempted from the fully adducted position against resistance, while the muscle is palpated superior to the spine of the scapula.b. Infraspinatus. The infraspinatus occupies the medial three quarters of the infraspinous fossa and is partly covered by the deltoid and trapezius. In addition to helping stabilize the glenohumeral joint, the infraspinatus is a powerful lateral rotator of the humerus. To test the infraspinatus, the person flexes the elbow and adducts the arm. The arm is then laterally rotated against resistance. If acting normally, the muscle can be palpated inferior to the scapular spine. To test the function of the suprascapular nerve, which supplies the supraspinatus and infraspinatus, both muscles must be tested as described.c. Teres Minor. The teres minor is a narrow, elongate muscle that is completely hidden by the deltoid, and is often not clearly delineated from the infraspinatus. The teres minor works with the infraspinatus to rotate the arm laterally and assist in its adduction. The teres minor is most clearly distinguished from the infraspinatus by its nerve supply. The teres minor is supplied by the axillary nerve, whereas the infraspinatus is supplied by the suprascapular nerve.d. Subscapularis. The subscapularis is a thick, triangular muscle that lies on the costal surface of the scapula, and forms part of the posterior wall of the axilla. It crosses the anterior aspect of the scapulohumeral joint on its way to the humerus. The subscapularis is the primary medial rotator of the arm and also adducts it. It joins the other rotator cuff muscles in holding the head of the humerus in the glenoid cavity during all movements of the glenohumeral joint (i.e., it helps stabilize this joint during movements of the elbow, wrist, and hand).
Supraspinatus
Infraspinatus
Teres major
Subscapularis
Back, Deltoid, and Scapular Region