Muscle Anatomy

-aids muscle of back in trunk rotation and lateral flexion -oblique curls

Compresses abdominal contents

Origin- occipital bone, ligumentum nuchae, spine c₇ and all thoracic vertabrae Insertion- acromion and spinous process of scapula, lateral third of clavicle -extends head -stablizes scapula

-prime mover of arm extension -adducts and medial rotates arm

- lateral rotation of humerous -stabilizes shoulder

-origin: lateral margin of scapula -insertion: greater tubercle of humerous -helps hold head of humerous in gleniod cavity

-extends, medially rotates, and adducts humerous

-assists abduction of humerous

-elevates and adducts scapula

-origin: spinous process of c7 and t1-t5 -insertion: medial border of scapula -pulls scapula medially

-extend head and vertebral column

-extend and bend vertebral column laterally

-extend of hyperextend head

-prime mover of arm extension -adducts medially rotates arm

-moves scapula forward toward chest wall