Muscles that move the upper arm (humerus)

Where do all of these muscles insert?

humerus

pectoralis major

Origin: ribs 2-6

Action: flexion of the humerus and adducts humerus

latissimus dorsi

Origin: lower thoracic and lumbar vertebra (t8-L5)

Action: extend and adducts the humerus

Subscapularis

origin: subscapular fossa of scapula

Action: medially rotates the humerus

Coracobrachialis

Origin: Coracoid process of the scapula

Action: flex the humerus

Deltoid

Origin: clavicle and scapula

Action: abduct the arm

Supraspinatus

origin: supraspinous fossa

Action: abduct the humerus

What is the supraspinatus muscles responsible for ?

First 15 degree arm raise then deltoid takes over

infraspinatus muscle

origin: infraspinous fossa of scapula

Action: laterally rotate humerus

teres major

Origin: scapula

Action: internal (medial) rotate

Teres minor

Origin: infraspinous fossa

Action: laterally rotate humerus

What are the rotator cuff muscles? (SITS)

1. supraspinatus

2. infraspinatus

3. teres minor

4. subscapularis