Extensor Digitorum Brevis

At the medial ankle, the tibial nerve, a continuation of the medial trunk of the sciatic nerve, passes deep to the flexor retinaculum in the space between the medial malleolus and the medial wall of the calcaneus (Fig. 16.10a). The retinaculum consists of a thin fascia and forms the roof of the tarsal tunnel (Fig. 16.10). In addition to the nerve, the tarsal tunnel encloses the tibialis posterior, flexor digitorum longus and flexor hallucis longus tendons, the posterior tibial artery and two veins (Fig. 16.10a,b). Posteroinferior to the medial malleolus, the tibial nerve divides into the medial and lateral plantar nerves and the calcaneal nerve, which is responsible for the sensitive supply of the heel (Fig. 16.11). The plantar nerves supply the intrinsic foot muscles, except for the extensor digitorum brevis, which is innervated by the deep peroneal nerve. The posterior tibial artery accompanies the nerve deep to the flexor retinaculum and, inferior to the medial malleolus, it divides into medial and lateral plantar arteries (Fig. 16.11). 

EXTENSOR DIGITORUM BREVIS AND EXTENSOR HALLUCIS BREVIS... 

Extensor Digitorum Brevis and Extensor HaUucis Brevis... 

Lateral (wrist extensor) and supinator Supplied by the radial and the posterior interosseous nerve, this group consists of the supinator, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum communis, and the extensor carpi ulnaris. 

Anderson MW, Benedetti P, Walter Jet al (1995) MR appearance of the extensor digitorum manus brevis muscle a pseudotumor of the hand. AJR Am J Roentgenol 164 477-1479... 

If the electrode is inserted too proximally it will be in the extensor carpi radialis brevis if inserted too distally it will be in the extensor pollicis brevis if it is inserted too ulnarly or too superficial, it will be in the extensor digitorum communis. 

---