Peroneal motor nerve conduction study is commonly done by recording over the extensor digitorum brevis. Since atrophy of extensor digitorum brevis is not rare, proximal peroneal nerve conduction study is often needed recording over tibialis anterior. To decide optimal position of active electrode in proximal peroneal nerve conduction study, we selected 4 sites between tibial tuberosity & lateral malleolus, and analyzed waveforms of compound motor action potentials in 20 healthy subject.

The best recording site was proximal 2/5 or 40% between tibial tuberosity & lateral malleolus, showing maximal amplitude & optimal waveforms. Mean latency & amplitude at this site were 3.76±0.40 msec and 13.25±1.18 mV, and the mean distance between stimulating & recording elecrode was 13.50±0.85 cm.