An accessory flexor digitorum longus muscle with high division of the tibial nerve.

An accessory flexor digitorum longus muscle associated with a high division of the tibial nerve was encountered during routine dissection in the right leg of a newborn cadaver. The tibial nerve divided into its two terminal branches at a higher level than normal with a small branch from the tibial nerve contributing to one of the terminal branches. In addition, an accessory flexor digitorum longus muscle was observed to pass between the terminal branches of the tibial nerve.