An Extensor Digitorum Muscle for Index Finger Originated from the Extensor Carpi Radialis Brevis

Abstract

The anomalous variations in the extensor carpi radialis brevis (ECRB) and extensor digitorum (ED) muscles of the forearm have been previously reported in the literature. The present article reported an anomalous variation of the ECRB and ED muscles in the forearm. We found an accessory muscle originated from the medial side of the ECRB muscle and inserted into the base of second metacarpal bone. And the ED muscle divides into three distinct tendons without the tendon of index finger. This case is a first report of the variations of ECRB and ED muscle in Korean cadaver. Knowledge of this variation is important to avoid surgical complications and to prevent diagnostic problems. Its embryological and clinical significances were discussed.