Muscles Connecting the Scapula to the Humerus

Lateral third of clavicle, acromion, spine of scapula

Deltoid origin

Middle of lateral surface of shaft of humerus

Deltoid insertion

Axillary nerve

Deltoid nerve

Abducts arm; anterior fibers flex and medially rotate arm; posterior fibers extend and laterally rotate arm

Deltoid action

Supraspinous fossa of scapula

Supraspinatus origin

Greater tuberosity of humerus; capsule of shoulder joint

Supraspinatus insertion

Suprascapular nerve

Supraspinatus nerve

Abducts arm and stabilizes shoulder joint

Supraspinatus action

Infraspinous fossa of scapula

Infraspinatus origin

Greater tuberosity of humerus; capsule of shoulder joint

Infraspinatus insertion

Suprascapular nerve

Infraspinatus nerve

Laterally rotates arm and stabilizes shoulder joint

Infraspinatus action

Lower third of lateral border of scapula

Teres major origin

Medial lip of bicipital groove of humerus

Teres major insertion

Lower subscapular nerve

Teres major nerve

Medially rotates and adducts arm and stabilizes shoulder joint

Teres major action

Subscapular fossa

Subscapularis origin

Lesser tuberosity of humerus

Subscapularis insertion

Upper and lower subscapular nerves

Subscapularis nerve

Medially rotates arm and stabilizes shoulder joint

Subscapularis action