Posterior brachial cutaneous nerve
Nervus cutaneus posterior brachii
- Latin synonym: Nervus cutaneus brachii posterior
- Synonym: Posterior cutaneous nerve of arm
- Related terms: Posterior cutaneous nerve of arm; Posterior brachial cutaneous nerve; Posterior cutaneous nerve of arm; Posterior brachial cutaneous nerve (Radial nerve)
Definition
The posterior brachial cutaneous nerve, a.k.a. the posterior cutaneous nerve of the arm, is a sensory nerve derived from the radial nerve.
Origin
This nerve arises from the radial nerve in the axillary region, branching off before the radial nerve passes through the triangular space—bounded by the humerus, long head of the triceps brachii, and teres major muscle—and then travers the spiral groove on the posterior surface of the humerus.
Course and innervation
After branching from the radial nerve, the posterior brachial cutaneous nerve pierces the deep fascia of the posterior arm. It descends distally to supply cutaneous sensation to the skin of the lower posterior arm, spanning from the posterior axillary fold down to the olecranon process of the ulna.
Injury to the posterior brachial cutaneous nerve can result in sensory deficits, including numbness, paresthesias, or pain in its innervation territory on the posterior arm.
References
Gray, H. (2016). ‘Chapter 48: Shoulder girdle and arm’ in Gray’s anatomy the anatomical basis of clinical practice. (41st ed.) New York: Elsevier, pp. 833.
Baglien P, Varacallo MA. Anatomy, Shoulder and Upper Limb, Cutaneous Innervation. [Updated 2023 Jul 24]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK545249/
Glover NM, Black AC, Murphy PB. Anatomy, Shoulder and Upper Limb, Radial Nerve. [Updated 2023 Nov 5]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK534840/
