Levator scapulae muscle
Anatomy and supply
The levator scapulae is a long muscle of the shoulder girdle. It originates at the transverse processes of the atlas and axis as well as the posterior tubercles of the 3rd-4th cervical vertebrae. It inserts at the superior angle and medial border of the scapula. The upper part of this muscle lies under the splenius capitis and sternocleidomastoideus muscles, and its' lower part under the trapezius. Only the middle part of the levator scapulae remains uncovered in the lateral cervical region and for that reason the muscle can be most easily palpated in this area. The levator scapulae is supplied by the dorsal scapular nerve (C4-C5), a branch of the brachial plexus.
As the name indicates, the main function of the levator scapulae is the elevation of the scapula. Thereby it simultaneously pulls the entire scapula medially. This movement is helpful when bringing the elevated arm back to the neutral position. In addition, the muscle also moves the inferior angle away from the back causing a small upward tilt of the scapula. If the scapula is fixed, a contraction of the levator scapulae leads to the bending of the cervical vertebral column to the side (lateral flexion).
An isolated lesion of the dorsal scapular nerve with a consequent paralysis of the levator scapulae muscle is very rare. The symptoms include a “winging” of the scapula (scapula alata) as well as an atrophy of both the levator scapulae and rhomboid muscles. As the affected patients may have no clear complaints the correct diagnosis is often made too late. The levator scapulae is one of the muscles of the human body which is prone to stiffening and chronic pain due to false posture in everyday life. Common causes are, among others, carrying heavy shoulder bags, permanent lifting of the shoulders while sitting at a desk and sleeping on one side of the body without proper head support.