Pectoral Girdle Muscles

Pectoralis minor

Depresses & protracts shoulder; rotates scapula so glenoid cavity moves inferiorly

Serratus anterior

Prime mover - protracts shoulder; rotates scapula so glenoid cavity moves superiorly;abducts & raises arm horizontally (pushing/punching = boxer’s muscle)

Trapezius

Stabilizes, raises/elevates (Shrugging!), retracts (adducts) & rotates scapula

Levator Scapulae

Elevates scapula

Rhomboids Major & Minor

Adducts scapula; downward rotation

Pectoralis major

Prime mover of arm flexion; adduction & medial rotation at shoulder (helps with climbing, throwing, pushing)

Deltoid

Prime mover of arm abduction; arm flexion & medial rotation (anterior part); arm extension & lateral rotation (posterior part)

Latissimus dorsi

Prime mover of arm extension; adduction; medial rotation at shoulder; brings arm down in power stroke (hammering, swimming, rowing)

Subscapularis

Chief medial rotator of humerus (holds head of humerus in glenoid cavity)

Supraspinatus

Initiates abduction; helps prevent downward dislocation of humerus

Infraspinatus

Rotates humerus laterally (holds head of humerus in glenoid cavity)

Teres minor

Rotates humerus laterally (holds head of humerus in glenoid cavity)

Teres major

Extends, medially rotates & adducts humerus (synergist with lat dorsi)