It appears between the contiguous borders of supinator muscle and the abductor pollicis longus muscle, and runs down the back of the forearm between the superficial and deep layers of muscles, to both of which it distributes branches.

Where it lies on abductor pollicis longus muscle and the extensor pollicis brevis muscle, it is accompanied by the dorsal interosseous nerve.

At the lower part of the forearm it anastomoses with the termination of the volar interosseous artery, and with the dorsal carpal network.

[1] This ascends to the interval between the lateral epicondyle and olecranon, on or through the fibers of supinator muscle, but beneath the anconeus muscle, and anastomoses with the middle collateral branch of the deep artery of arm, the posterior ulnar recurrent artery and the inferior ulnar collateral artery.

[1] This article incorporates text in the public domain from page 596 of the 20th edition of Gray's Anatomy (1918)