Male Extensor Carpi Ulnaris Muscle, Posterior View

Description

Posteriorly, the extensor carpi ulnaris is presented as a fusiform muscle along the ulnar side of the forearm, its proximal fibers arising near the lateral epicondyle of the humerus and the dorsal border of the ulna before tapering into a tendon that tracks distally toward the ulnar head. The muscle belly sits superficial in the posterior compartment, lateral to the subcutaneous border of the ulna but medial to the extensor digiti minimi and extensor digitorum tendons as they approach the dorsum of the wrist. At the distal forearm, its tendon aligns with the sixth dorsal compartment beneath the extensor retinaculum, coursing toward the base of the fifth metacarpal. Clear ulnar-sided topography. Clinically, this posterior orientation is the one you want when teaching ulnar-sided wrist pain because it frames the extensor carpi ulnaris tendon where it most often becomes symptomatic. Tendinopathy and tenosynovitis concentrate near the ulnar styloid, and subsheath injury can allow tendon subluxation during supination and ulnar deviation, a common problem in racquet and stick sports. The relationship to the distal radioulnar joint and triangular fibrocartilage complex helps explain why ECU pathology and TFCC tears can coexist and why palpation over the sixth compartment can be a discriminating exam step. Use this artwork for upper limb anatomy labs, sports medicine teaching files, and operative atlases discussing dorsal ulnar wrist approaches, including ECU tendon stabilization and sixth-compartment release. It also fits well in radiology education when correlating surface anatomy with ultrasound assessment of ECU tenosynovitis and dynamic subluxation. Anatomical accuracy verified by SciePro's Medical Advisory Board.