Levator scapulae

The levator scapulae (Latin: musculus levator scapulae) is a long and relatively thin extrinsic muscle of the back located on either side of the neck. Its superior parts are covered by the sternocleidomastoid muscle, while the lower aspects are situated inferior to the trapezius. The middle part of the muscle is the only portion that can be easily palpable in the lateral neck region as it is not covered by any other muscles.

The levator scapulae muscle participates in forming the posterior neck triangle floor. It belongs to the superficial muscles of the back. Besides that, the levator scapulae muscle is also classified as one of the shoulder muscles. It extends from the upper cervical vertebrae to the scapula. As the name suggests, the primary function of the levator scapulae muscle is to elevate the scapula.

Origin

The levator scapulae muscle originates from the posterior tubercles of the transverse processes of the first four cervical vertebrae (C1 - C4).

Insertion

The levator scapulae inserts on the medial margin of the scapula between the superior angle and the root of the scapular spine.

Action

The levator scapulae muscle primary elevates the scapula. This muscle also inferiorly rotates the scapula and depresses the glenoid cavity. If the scapula is fixed, the levator scapulae assists in lateral flexion of the neck to the ipsilateral side and extension of the neck.

Innervation

The levator scapulae is innervated by the anterior rami of the third and fourth cervical spinal nerves (C3 - C4) and the dorsal scapular nerve. The cervical spinal nerves arise from the cervical plexus, while the dorsal scapular nerve is a branch of the fifth cervical spinal nerve (C5).

Blood supply

The levator scapulae muscle receives arterial blood supply from the dorsal scapular artery. The dorsal scapular artery usually arises from the subclavian artery, although it can also arise from the transverse cervical artery.