Levator scapulae muscle
There is a levator scapulae on each side of the spine. It originates at the 4th vertebrae of the neck and extends to the corner of the shoulder blade. It is one of the muscles in the axioscapular muscle group and works in conjunction with the serratus anterior, rhomboid major, and the rhomboid minor muscles. As the name suggests, the levator scapulae muscles are responsible for raising and lower the shoulders. In the neck it works to bend or rotate the head to one side, or working as a pair, to tilt the head backwards. It may also constrict involuntarily in times of stress, causing tension in the neck and upper back and a slight elevation of the shoulders.
The main blood supply for this muscle is the dorsal scapular artery and the nerves originate in the 4th and 5th cervical nerves.