Initiation of abduction at shoulder joint is done by?
ANSWER: (C) Supraspinatus REF: Snells Anatomy 8th ed Ch: 9 Movements possible at shoulder joint areFlexion: Normal flexion is about 90deg and is performed by the anterior fibers of the deltoid, pectoralis major, biceps, and coracobrachialis muscles.Extension: Normal extension is about 45deg and is performed by the posterior fibers of the deltoid, latissimus dorsi, and teres major muscles.Abduction: Abduction of the upper limb occurs both at the shoulder joint and between the scapula and the thoracic wall . The middle fibers of the deltoid, assisted by the supraspinatus, are involved. The supraspinatus muscle initiates the movement of abduction and holds the head of the humerus against the glenoid fossa of the scapula; this latter function allows the deltoid muscle to contract and abduct the humerus at the shoulder jointAdduction: Normally, the upper limb can be swung 45deg across the front of the chest. This is performed by the pectoralis major, latissimus dorsi, teres major, and teres minor muscles.Lateral rotation: Normal lateral rotation is 40deg to 45deg. This is performed by the infraspinatus, the teres minor, and the posterior fibers of the deltoid muscle.Medial rotation: Normal medial rotation is about 55deg. This is performed by the subscapularis, the latissimus dorsi, the teres major, and the anterior fibers of the deltoid muscle.Circumduction: This is a combination of the above movements.
Suprascapularis
Deltoid
Supraspinatus
Infraspinatus
Back, Deltoid, and Scapular Region