Levator scapulae muscle
The levator scapulae is a long and relatively thin superficial back muscle located on either side of the neck. It stretches between the scapula and cervical vertebrae. The upper part of this muscle lies beneath the sternocleidomastoid muscle, while its lower portion is located below the trapezius. The middle part is the only portion that can be easily palpable in the lateral neck as it is not covered by any other muscles.
The levator scapulae participates in forming the floor of the posterior neck triangle. Besides that, this muscle may also be classified as a muscle of the shoulder. As its name suggests, the primary function of the levator scapulae is to lift the scapula.
Origin: posterior tubercles of the transverse processes of the first four cervical vertebrae (C1 - C4).
Insertion: medial margin of the scapula between the superior angle and root of the spine.
Action: elevates the scapula, rotates it inferiorly, depresses the glenoid cavity and assists in extension and lateral flexion to the ipsilateral side of the neck.
Innervation: anterior rami of the third and fourth cervical spinal nerves (C3, C4) and dorsal scapular nerve (it is a branch of the fifth cervical spinal nerve (C5)).
Blood supply: dorsal scapular artery - a branch of either subclavian or transverse cervical artery.