Levator scapulae: origin, insertion, action and innervation

The levator scapulae is a strap-like muscle at the back and side of the neck that runs from the upper four cervical vertebrae down to the top corner of the shoulder blade. It lifts the scapula and turns it so the shoulder socket tilts down, and it is supplied by the dorsal scapular nerve and the C3 and C4 nerves.

Where it is

The levator scapulae lies in the side of the neck, under the upper part of the trapezius and the sternocleidomastoid. Between those two muscles, a short stretch of it is uncovered and forms part of the floor of the posterior triangle of the neck.

It starts as four separate slips, one from each of the top four cervical vertebrae. The slips join into one belly that runs down and back, with a slight twist, to the superior angle of the scapula, the upper inner corner of the shoulder blade.

It is the top member of a column of three muscles that all end on the medial border of the scapula, one above the other: the levator scapulae at the top, the rhomboid minor in the middle and the rhomboid major at the bottom.

Origin and insertion

• Origin: the transverse processes of the first four cervical vertebrae, the atlas (C1), the axis (C2), and C3 and C4 (on their posterior tubercles).
• Insertion: the medial border of the scapula, from the superior angle down to the root of the spine of the scapula.

What it does

With the neck held still, it moves the shoulder blade:

1. Elevation of the scapula. It shrugs the shoulder up, together with the upper fibers of the trapezius. It is at work when you carry a heavy bag on one shoulder and keep it from slipping.
2. Downward rotation of the scapula. Because it pulls on the upper inner corner, it turns the scapula so that the glenoid cavity tilts down. This helps bring a raised arm back to the side, working with the rhomboids and the pectoralis minor.

With the shoulder held still, it moves the neck:

1. Bends the neck to the same side when one side contracts, and helps extend it when both sides contract.

Innervation and blood supply

The levator scapulae has a double nerve supply. The dorsal scapular nerve (C5), the same nerve that supplies the rhomboids, reaches it from below. Branches from the anterior rami of C3 and C4 (the cervical plexus) reach it directly from above.

Its blood comes from the dorsal scapular artery and from the transverse cervical and ascending cervical arteries.

How to remember it

• Levator = lifter. Levare means "to raise" in Latin: the levator scapulae lifts the scapula.
• Four slips, four vertebrae. C1 to C4, then one belly to the superior angle.
• Top of the column. Levator, rhomboid minor, rhomboid major: from top to bottom down the medial border of the scapula, all supplied by the dorsal scapular nerve.
• Two nerves, two levels. C3 and C4 from the neck, plus C5 through the dorsal scapular nerve.

Review the muscles that steer the scapula on the muscles of the shoulder page, then find the levator scapulae in the shoulder quiz.

Frequently asked questions

What is the action of the levator scapulae?

It elevates the scapula and rotates it downward, tilting the glenoid cavity down. With the scapula fixed, it bends the neck to the same side.

Where does the levator scapulae attach?

From the transverse processes of C1 to C4 to the medial border of the scapula, between the superior angle and the root of the spine.

What nerve supplies the levator scapulae?

The dorsal scapular nerve (C5) and direct branches of the anterior rami of C3 and C4.

Is the levator scapulae a neck or a shoulder muscle?

Both. It lies in the neck and can bend it, but its main job is to move the scapula, so it is grouped with the muscles of the shoulder girdle.

Sources

• OpenStax, Anatomy and Physiology 2e, 11.5 Muscles of the pectoral girdle and upper limbs
• OpenStax, Anatomy and Physiology 2e, 7.3 The vertebral column
• Z-Anatomy, the libre 3D atlas of anatomy