Actions of the Shoulder Muscles

Both heads of the biceps brachii

Elbow flexion, forearm supination, shoulder flexion

coracobrachialis

shoulder flexion and adduction

anterior deltoid

shoulder flexion and medial rotation

middle deltoid

shouldre adduction

posterior deltoid

shoulder extension and lateral rotation

infraspinatus

shoulder lateral rotation

latissimus dorsi

shoulder extension, adduction, and medial rotation

levator scapulae

scapular elevation, downward rotation

pectoralis major both heads

shoulder horizontal adduction and medial rotationpe

pectoralis major clavicular head

shoulder flexion

pectoralis major sternal head

shoulder extension from a flexed position

pectoralis minor

scapular protraction, depression, downward rotation

rhomboid major and minor

scapular retraction, downward rotation, fixes scapula to thoracic wall

serratus anterior

scapular upward rotation, protraction, holds scapular medial border to thorax

subscapularis

shoulder medial rotation

supraspinatus

first 45 degrees of shoulder abduction

teres major

shoulder adduction, extension, medial rotation

teres minor

shoulder lateral rotation

all fibers of the trapezius

scapular retraction, upward rotation

upper trapezius fibers

scapular elevationl

lower trapezius fibers

scapular depression

long head of the triceps

shoulder and elbow extension