European Journal of Anatomy

Official Journal of The Spanish Society of Anatomy
Cover Volume 10 - Number 2
Eur J Anat, 10 (2): 79-81 (2006)

An accessory digastric abductor pollicis longus muscle: Report of a case

Rabi S., Indrasingh I., Koshy S., Holla S.J., Vettivel S., Suganthy J.

Department of Anatomy, Christian Medical College, Vellore 632 002, India

ABSTRACT 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 distal belly. It was adjacent to the abductor pollicis 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 retinaculum 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 compartments of the forearm, had developed from extensor and flexor muscles and were connected 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 accessory muscle may be associated with joint and neural symptoms.

Keywords: article, carpal bone, controlled study, dissection, flexor muscle, human, muscle contraction, stenosis, thenar

European Journal of anatomy
ISSN 2340-311X (Online)