origin insertion and actions

sternocleidomastoid

O- sternum and clavicle I- mastoid process of the temporal bone A- flexion of neck and rotation of head

trapezius

O- occipital bone, spinous processes of all thoracic vertebrae I- spine and acromion of scapula and lateral clavicle A- extend head, raises, adducts, and depresses the scapula

Serratus anterior

O- lateral aspect of ribs

I- medial order of the scapula

A- rotates scapula forward and upward

Pectoralis Minor

O- anterior of ribs 3-5

I- coracoid process of scapula

A- raises the ribs or pulls the scapula forward

pectoralis major

O- clavicle, sternum and cartilage of ribs 1-6

I- intertuberclar sulcus of humerus

A- flexes adducts and roates the humerus

latissimus dorsi

O- lower 6 thoracic vertebrae, lumbar vertebrae, illiac crest

I- intertubercular sulcus of humerus

A- extends adducts and rotates the humerus

rectus abdominis

O- pubic crest and symphysis

I- cartilage of ribs 5-7, xyphoid process of sternum

A- flexes and roates vertebral column, increases abdominal pressure, depresses ribs, stabilizes pelvis

externa olbique

O- anterior of lower 8 ribs

I- linea alva, illiac and pubix crest

A- flexes and roates vertebral column, increase abdominal pressure, depresses ribs, stabilizes pelvis