Tibial and common peroneal nerves

Polyfascicular echotexture of the tibial and common peroneal nerves in the popliteal fossa. Local anesthetic has been injected at the bifurcation of the sciatic nerve within the common investing fascial sheath and seen to track distally around and along these major branches. The common peroneal nerve (arrow) is smaller than the tibial nerve (dashed arrow) and lies closer to the posterior skin surface. The common peroneal nerve contains fewer but larger fascicles than the tibial nerve.