SUMMARY

During routine dissection, a variant muscle had a proximal fleshy belly arising from the upper part of the posterior surface of the radius, an intermediate tendon and a distal fleshy belly that joined the abductor pollicis brevis muscle. A branch from the posterior interosseous nerve innervated the proximal belly and the median nerve innervated the dis-tal belly. It was adjacent to the abductor pol-licis longus muscle. It was a digastric muscle that can be called the ‘accessory digastric abductor pollicis longus muscle’. The tendon of the palmaris longus muscle divided into two. One tendon joined the flexor retinacu-lum and the other tendon attached to the abductor pollicis brevis muscle. This slip to which the abductor pollicis brevis attached crossed over the median nerve. The two bellies of the variant muscle, which were supplied by the nerves of the flexor and extensor compart-ments of the forearm, had developed from extensor and flexor muscles and were connect-ed by an intermediate tendon. Although a similar muscle has been mentioned previously, here we report this variant muscle with a nerve supply and a new name for the first time in the Southern Indian population. This acces-sory muscle may be associated with joint and neural symptoms