Muscles of the Shoulder

Front

Deltoid

Back

muscle helps lift your arm in different directions.

P: Acromial end of clavicle; acromion and spine of scapula
D: Deltoid tuberosity of humerus

Axillary nerve (C5–C6)

Front

Supraspinatus

Back

Abducts arm

P: Supraspinous fossa of scapula
D: Greater tubercle of humerus

Front

Infraspinatus

Back

Laterally rotates arm (agonist); adducts arm

P: Infraspinous fossa of scapula
D: Greater tubercle of humerus

Front

Teres major

Back

Extends arm; adducts arm; medially rotates arm


P: Inferior lateral border and inferior angle of scapula

D: Lesser tubercle and intertubercular groove of humerus

Front

Teres minor

Back

Laterally rotates arm (agonist); adducts arm

P: Superoposterior lateral border of scapula (superior to teres major attachment)

D: Greater tubercle of humeru

Front

Subscapularis

Back

Medially rotates arm


P: Subscapular fossa of scapula
D: Lesser tubercle of humerus