Shoulder;

O: Clavicular head and sternal head, ribs 1-6 (cartilage), aponeurosis of external oblique muscle;

I: Intertubercular sulcus of humerus;

N: Lateral and Medial pectoral nerves;

A: Flexes, adducts, and rotates arm medially

Shoulder;

O: Lumbodorsal fascia, spinous processes of T7-T12 and lumbar vertebrae, iliac crest and inferior angle of scapula;

I: Intertubercular groove of humerus;

N: Thoracodorsal nerve;

A: Extension, powerful adductor, medial rotator of arm, depresses shoulder (used in climbing & swimming)

Shoulder;

O: Lateral 1/3 of clavicle, acromion process , and spine of scapula (lateral);

I: Deltoid tuberosity of humerus;

N: Axillary Nerve;

A: Abduction of arm ( all fibers), Flex and medially rotate arm-synergist with pectoralis major- (anterior fibers), extend and laterally rotate arm (posterior fibers)

Shoulder;

O: Subscapular fossa of scapula;

I: Lesser tubercle of humerus;

N: Subscapular nerves (upper and lower);

A: Major medial rotator of humerus

Shoulder;

O: Supraspinous fossa of scapula;

I: Superior part of greater tubercle of humerus;

N: Suprascapular nerve;

A: Abducts arm, stabilizes shoulder joint, and helps prevent downward dislocation of humerus

Shoulder;

O: Infraspinous fossa of scapula;

I: Greater tubercle of humerus (posterior to supraspinatus insertion;

N: Suprascapular Nerve;

A: Rotates arm laterally and aids in holding head of humerus in glenoid cavity

Shoulder;

O: Lateral border of dorsal scapular surface;

I: Greater tubercle of humerus (inferior to infraspinatus insertion);

N: Axillary nerve;

A: Same actions as infraspinatus muscle, aids in adduction of arm

Shoulder;

O: Posterior surface of scapular at inferior angle;

I: Intertubercular sulcus of humerus, tendon fused with tendon of latissimus dorsi;

N: Lower subscapular nerve;

A: Adducts, extends, and rotates arm medially (synergist with latissimus dorsi "little helper")

Shoulder;

O: Coracoid process of scapula;

I: Medial surface of humerus shaft (opposite of deltoid tubercle);

N: Musculocutaneous nerve;

A: Flexes and adducts arm (synergist with pectoralis major)