Extensor carpi ulnaris (ECU) muscle

Extensor carpi ulnaris (ECU) muscle is a muscle of the superficial layer of the posterior compartment of the forearm. It is separated from the extensor digitorum and the extensor digiti minimi muscles by a distinct intermuscular septum. It is the only forearm extensor that lies in its own fibro-osseous tunnel at the level of the wrist with its own subsheath as it passes through the 6extensor compartment of the wrist. At the level of the ulna, it is covered by a subsheath, extensor retinaculum and the linea jugata. It is one of the extrinsic muscles of the hand.

Summary

• origin: lateral epicondyle of humerus, radial collateral ligament and posterior border of ulna
• insertion: base of 5metacarpal on posterior surface
• arterial supply: radial recurrent artery and posterior interosseous artery
• innervation: posterior interosseous nerve (C7 and C8), a continuation of the deep branch of the radial nerve (C7, C8)
• action: extension and adduction (i.e. ulnar deviation) of the wrist joint

Related pathology

• tendinosis and/or tenosynovitis
  • ECU is the second most common site of upper limb tenosynovitis
• subluxation of the ECU tendon with subsheath injury

Siehe auch:

• Sehnenfächer Handgelenk
• Handgelenksmuskulatur
• Extensoren des Unterarmes
• Subluxation Musculus extensor carpi ulnaris

und weiter:

• Extensoren
• extensor carpi ulnaris subsheath injury
• Tendovaginitis Musculus extensor carpi ulnaris