Entrapment neuropathies of the foot. Electromyographic techniques.

Entrapment neuropathies frequently involve the foot. The diagnosis can be established by electrophysiological techniques for the exploration of muscles and nerves. Needle recording from the intrinsic foot muscles is a valuable asset in the detection of neurogenic syndromes. The motor and sensory nerve conduction velocities are determined using surface electrodes. The sensory nerve conduction study can be supplemented with somatosensory-evoked-potential studies. Based on these investigations, the location, severity and prognosis of the nerve lesion can be determined. In the presence of tunnel and compression syndromes involving the foot, studies of the tibial nerve (tarsal tunnel - Morton), peroneal nerve and sural nerve are of particular interest.