Shoulder

Muscle	Origin	Insertion	Action
Deltiod(anterior)	Lateral 1/3 of clavicle	Deltoid tuberosity of humerus	Abduction, horizontal flexion, medial rotation (of humerus at shoulder)
Deltoid(middle)	Superior surface of acromion process	Tuberosity of humerus	Abduction of shoulder
Deltoid(posterior)	Inferior part of spine of scapula	Tuberosity of humerus	Abduction, horizontal extension and lateral rotation of shoulder
Pectoralis major(sternal)	Sternum to 7th rib, artilae of tru ribs, external oblique muscles	Humerus	Flexion, adduction, medial rotation, horizontal flexion of shoulder; Depresses, protracts and rotates scapula downwards
Pectoralis major(clavicular)	Anterior surface of medial 1/2 of clavicle	Humerus	Flexion, adduction, horizontal flexion, medial rotation of shoulder
Coracobrachialis	Tip of coracoid process of scapula	Middle medial border of humerus	Horizontal flexion, adduction of shoulder
Latissimus dorsi	Lower 6 thoracic vertebra, all lumbar vertebrae, posterior crest of ilium, posterior surface of sacrum, lower 3-4 ribs, iniferior angles of scapula	Humerus	Extends, retracts, medially rotates shoulder; depresses, retracts and rotates scapula downwards. Assists in forced expiration.
Teres Major	Dorsal surface of inferior angle of scapula on lower 1/2 of scapular border	Medial part of humerus	Adducts, medially rotates humerus at shoulder. Extends shoulds.
Supraspinatus (Rotator cuff)	Medial 2/3 of supraspinous fossa	Superior surface of humerus	Abduction of humerus at shoulder
Infraspinatus (Rotator cuff)	Infraspinous fossa of scapula	Posterior part of humerus	Lateral rotation of humerus at shoulder
Teres minor (Rotator cuff)	Superior 2/3 of dorsal surface of border of scapula	Inferior part of humerus	Lateral rotation of humerus at shoulder
Subscapularis(Rotator Cuff)	Anterior surface of subscapular fossa	Lesser rubercles of humerus	Medial rotation of humerus at shoulder