<P> The levator scapulae is supplied by two or three branches of the fourth and fifth cervical nerves, and frequently by a branch from the dorsal scapular nerve . </P> <P> The levator scapulae is supplied by the dorsal scapular artery . Normally, this artery has a small branch which passes laterally to the supraspinatus fossa of the scapula, and in a third of cases, this branch supplies the muscle . If the dorsal scapular artery comes off the transverse cervical artery, the parent transverse cervical artery splits, the dorsal scapular artery passes medially, while the transverse cervical artery passes laterally . </P> <P> When the spine is fixed, levator scapulae elevates the scapula and rotates its inferior angle medially . It often works in combination with other muscles like the rhomboids and pectoralis minor to rotate down . </P> <P> Elevating or rotating one shoulder at a time would require muscles to stabilize the cervical spine and keep it immobile so it does not flex or rotate . Elevating both at once with equal amounts of pull on both side of cervical spinal origins would counteract these forces . Downward rotation would be prevented by co-contraction of other muscles that elevate the spine, the upper fibers of the trapezius, which is an upward rotator . </P>

What is the action of the levator scapula