The Ulnar Nerve


	Head and Neck

	Vagus (X)

	Spinal Accessory Nerve (XI)

	Cervical Plexus (C2-4)

	Brachial Plexus (C5-T1)

	Upper Extremity

	Musculocutaneous

	Radial

	Median

	Ulnar

	Lower Extremity

	Ilioinguinal / Iliohypogastric

	Femoral

	Sciatic

	Common Peroneal

	Tibial

	Sural

The ulnar nerve arises from the medial cord of the brachial plexus. In the arm the ulnar nerve usually lies between the axillary artery and axillary vein in the axilla.

The Ulnar Nerve in the Forearm (supine with arm supinated)

The ulnar nerve is a bright (echogenic) triangular or oval nerve distal to the elbow. The ulnar nerve joins the ulnar side of the ulnar artery in the forearm (Video 384 KB) where it is surrounded by the flexor digitorum superficialis (FDS), flexor digitorum profundus (FDP) and flexor carpi ulnaris (FCU) muscles. In the distal forearm the ulnar nerve will lie adjacent to the FCU tendon.

(Roll cursor over image to see labels.)

Palmar and dorsal cutaneous branches of the nerves to the hand are given off proximal to the wrist (especially the dorsal cutaneous branch of the ulnar nerve, (Video 332 KB)). A relatively common (3-10%) anatomic variant is superficial ulnar artery, where the ulnar artery instead lies superficial to the flexor muscles.

References

Gray AT, Schafhalter-Zoppoth I. Ultrasound guidance for ulnar nerve block in the forearm. Reg Anesth Pain Med. 2003 Jul-Aug;28(4):335-9. PMID: 12945028

Schafhalter-Zoppoth I, Gray AT. Ultrasound-guided ulnar nerve block in the presence of a superficial ulnar artery. Reg Anesth Pain Med. 2004 May-Jun;29(3):297-8. PMID: 15138917

Heinemeyer O, Reimers CD. Ultrasound of radial, ulnar, median, and sciatic nerves in healthy subjects and patients with hereditary motor and sensory neuropathies. Ultrasound Med Biol. 1999 Mar;25(3):481-5. PMID: 10374990

Peeters EY, Nieboer KH, Osteaux MM. Sonography of the normal ulnar nerve at Guyon's canal and of the common peroneal nerve dorsal to the fibular head. J Clin Ultrasound. 2004 Oct;32(8):375-80. PMID: 15372443

Jacob D, Creteur V, Courthaliac C, Bargoin R, Sassus B, Bacq C, Rozies JL, Cercueil JP, Brasseur JL. Sonoanatomy of the ulnar nerve in the cubital tunnel: a multicentre study by the GEL. Eur Radiol. 2004 Oct;14(10):1770-3. PMID: 15258824

Peer S, Bodner G (editors). High-Resolution Sonography of the Peripheral Nervous System. Springer Verlag, 2003. ISBN: 3540432604.