Quick Facts
Origin: Radial nerve (C5).
Course: Arises from the radial nerve before it enters the spiral groove.
Branches: No named branches.
Supply: Skin of the back of the arm from the insertion of the deltoid to the olecranon process of ulna.
Related parts of the anatomy
Origin
The posterior brachial cutaneous nerve is a branch of the radial nerve.
Course
In the upper part of the arm, the radial nerve descends posterolaterally through the lower triangular space to enter the radial groove along with the profunda brachii vessels. Before entering the spiral groove in the midarm, it gives off the posterior brachial cutaneous nerve (which innervates a strip of skin overlying the triceps muscle).
Branches
There are no named branches.
Supplied Structures
The posterior brachial cutaneous nerve provides cutaneous innervation to the skin of the back of the arm, from the insertion of the deltoid to the olecranon process of ulna.
