Levator scapulae is one of the muscles within the floor of the posterior triangle of the neck on each side. Its superior part is covered by sternomastoid; its inferior part is deep to trapezius.
It has a tendinous origin from the transverse processes of the upper three or four cervical vertebrae. For each, the origin is just posterior to the origins of scalenus medius.
Running inferiorly, the tendons become a unified muscular belly. This inserts into the vertebral border of the scapula between its superior angle and the base of the spine.
Innervation is derived from two sources:
- anterior rami of third and fourth cervical nerves (C3,C4) from the cervical plexus
- dorsal scapular nerve (C5), which also supplies the rhomboids
Its functions are similar to the rhomboids:
- elevation of pectoral girdle, or conversely, limit its inferior displacement when the girdle is pulled downwards
- retraction of the pectoral girdle
- extension of the neck as a result of bilateral contraction, assisted by other muscles e.g. trapezius
- assists in laterally flexing the neck to the side of unilateral contraction
- rotation of the scapula so as to tilt the glenoid cavity inferiorly
- stabilisation of the scapula in conjunction with other muscles
Testing of levator scapulae is considered in the submenu.