Human muscle ( Trunk)

Elevates rib cage ( inhalation ) (2)

External intercostal -O: inferior border is rib. I: superior border of rib

Diaphragm- O; inferior internal rib cage. I: central tendon A: Prime mover

Depresses ribcage ( exhalation )

Internal intercostal

O: superior border of rib

I :inferior border of rib

Abdominal muscles (3)

1) external oblique ( runs at an right angle) O: lower 8 ribs. I: linea alba , iliac crest. A: trunk rotation and lateral Flexion

2) internal oblique ( runs at an left angle )O: iliac crest . I: linea alba, pubic crest. A: same as external oblique

3) transversus abdominus ( runs parallel)O: iliac crest. I: pubic crest.A compresses abdomen

Linea alba ( CT) where the abdominal muscles insert

Rectus abdominus

O: on pubis

I: on xiphoid process

A:flex and rotated lumbar region of vertebral column

Posterior

Latissimus Dorsi-O: lower 3 ribs. I; humerus. A: prime mover of arm extension

Teres major - O: scapula. I; humerus . Extends , medically rotates and adducts arm

Trapezius - O: occipital bone . I; scapula and clavicle. A: rotates and stabilizes scapula

Rotator cuff ( rotates arm 4)

-subscapularis: O: scapula. I: humerus. A: prime mover

-supraspinatus : O: scapula. I: humerus. A : abducts arm

-infraspinatus: O: scapula. I: humerus. A rotates arm laterally

-teres minor: O: scapula I : humerus . A: rotates arm laterally

Erector spinae

prime mover of back extension )

Rhomboids( stabilizes scapula )

O: spinous processes

I : scapula

Deltoid( prime mover of abduction of arm)

O: clavicle

I: humerus

pectoralis major

O; end of clavicle , sternum

I: greater tubercle of humerus

A: adducts and medically rotates arm