The interosseous nerve of the leg (lat. n. interosseus cruris) is a nerve of the lower limb, extending from the common peroneal nerve.
The interosseous nerve of the leg innervates the muscles of the anterior group of the leg - the long extensor of the fingers, the long extensor of the big toe and the third peroneal muscle. In addition, the interosseous nerve of the leg innervates the interosseous muscles of the leg and gives off sensory branches to the lateral surface of the leg.
The interosseous nerve of the leg arises from the common peroneal nerve approximately at the level of the upper third of the leg. The nerve then passes obliquely downward and laterally, located between the interosseous membrane and the tibialis anterior muscle. In the distal third of the leg, the interosseous nerve of the leg is divided into anterior and posterior branches, innervating the muscles of the anterior group of the leg.