Dorsal scapular nerve

At a glance

English

Dorsal scapular nerve

Latin (TA2)

Nervus dorsalis scapulae

System

Nerve

Region

Neck

Side

Paired, left and right

About the dorsal scapular nerve

The dorsal scapular nerve is one of the few branches taken straight from a root of the brachial plexus rather than from a trunk or cord. Its fibres come mainly from the anterior ramus of C5, sometimes with a contribution from C4, and it leaves that ramus close to the intervertebral foramen, before the root joins C6 to make the upper trunk.

From its origin the nerve usually passes backwards through the middle scalene, then descends behind the neck under cover of levator scapulae. It continues down along the medial (vertebral) border of the scapula, lying deep to rhomboid minor and then rhomboid major and giving twigs into each. Along this last stretch it keeps company with the dorsal scapular artery, or, where that vessel is missing, with the transverse cervical artery's deep branch.

Its muscles work together on the shoulder blade. The two rhomboids draw the scapula towards the spine and help rotate the glenoid downwards, while levator scapulae lifts the scapula and tilts it the same way. Acting as a group they hold the scapula against the chest wall, giving the arm a steady base for pushing and pulling.

Damage confined to this nerve is unusual, because it lies deep and is protected by muscle. When it does occur, often where the nerve is caught as it crosses the scalenes, the scapula on that side rests further from the midline and its medial border may lift slightly from the ribs. The person struggles to brace the shoulders back. Entrapment can also produce an aching pain along the inner edge of the shoulder blade with a reduced range of shoulder movement; most cases settle with conservative care.

Course and supply

Arises from

Anterior ramus of the fifth cervical nerve (C5), often with a small contribution from C4, close to the intervertebral foramen.

Ends in

Ends in muscular branches to levator scapulae, rhomboid minor and rhomboid major along the medial border of the scapula.

Supplies

Purely motor: supplies the rhomboids, which retract the scapula and rotate the glenoid downwards, and helps supply levator scapulae, which elevates the scapula. It carries no named skin territory.

Blood supply

Runs with the dorsal scapular artery, or with the transverse cervical artery's deep branch where that artery is absent.