At the level of the wrist, the extensor tendons are divided into six compartments by tough fibrous septae of the extensor retinaculum, numbered from radial to ulnar. This definition incorporates text from a public domain edition of Gray's Anatomy (20th U.S. The extensor muscles of the wrist and hand are contained within the dorsal aspect of the forearm and are all innervated by the radial nerve. Extensor tendons are located on the back of the hands and fingers thus making them susceptible to even the slightest injuries. The sheaths lining these compartments extends from above the dorsal carpal ligament those for the tendons of Abductor pollicis longus, Extensor brevis pollicis, Extensores carpi radialis, and Extensor carpi ulnaris stop immediately proximal to the bases of the metacarpal bones, while the sheaths for Extensor communis digitorum, Extensor indicis proprius, and Extensor digiti quinti proprius are prolonged to the junction of the proximal and intermediate thirds of the metacarpus. (5) opposite the interval between the radius and ulna, for the Extensor digiti quinti proprius (Ħ) between the head and styloid process of the ulna, for the tendon of the Extensor carpi ulnaris.

(4) to the medial side of the latter, for the tendons of the Extensor digitorum communis and Extensor indicis proprius (3) about the middle of the dorsal surface of the radius, for the tendon of the Extensor pollicis longus (2) behind the styloid process, for the tendons of the Extensores carpi radialis longus and brevis each tunnel is lined internally by a synovial sheath and separated from each other by fibrous septa. (1) on the lateral side of the styloid process, for the tendons of the Abductor pollicis longus and Extensor pollicis brevis Extensor Tendon Compartments of the Wrist Click card to see definition the 6 tunnels which transmit the long extensor tendons from the forearm into the hand located on the posterior aspect of the wrist. One is found in each of the following positions:

Between the dorsal carpal ligament and the bones six compartments are formed for the passage of tendons, each compartment having a separate mucous sheath.

Extensor tendon compartments