Shoulder anatomy

Action of shoulder Muscles

Abduction: middle deltoid, supraspinatus, anterior deltiod, posterior deltoid

Adduction: pectoralis major, teres major, latissimus dorsi, long head of triceps, coracobrachialis

Extension: latissimus dorsi, teres major, subscapularis, posterior deltoid, long head of triceps

Flexion: anterior deltoid, pectoralis major, long head of biceps, coracobrachialis

External rotation: infraspinatus, teres minor, posterior deltoid

Internal rotation: subscapularis, pectoralis major, latissimus dorsi, teres major, anterior deltoid