Muscle Actions

Trapezius

Elevate shoulder, depress shoulder, retract scapula medially

Latissimus dorsi

Extend & adduct humerus

Levator scapulae

Elevate scapula

Rhomboid minor

Depress glenoid fossa, retract scapula

Rhomboid major

Depress glenoid fossa, retract scapula

Pectoralis major

Adduct humerus, protract scapula, medially rotate humerus

Pectoralis minor

Holds scapula against thoracic wall

Subclavius

Anchors clavicle to first rib

Serratus anterior

Protract scapula

Deltoid

Abduct humerus, medially & laterally rotate humerus

Teres major

Adduct humerus

Supraspinatus

Holds humeral head in glenoid fossa; lateral rotation

Infraspinatus

Holds humeral head in glenoid fossa; lateral rotation

Teres minor

Holds humeral head in glenoid fossa; lateral rotation

Subscapularis

Holds humeral head in glenoid fossa; medial rotation

Coracobrachialis

Adduct humerus, flex arm

Biceps brachii

Supinates forearm, flexes supine forearm; helps hold humeral head in glenoid fossa

Brachialis

Flexes forearm in all positions

Triceps brachii

Extends forearm; resists dislocation of shoulder

Anconeus

Extends forearm