2026 Workshop Handout Bundle-W102G - NCS in the Foot Handout

W102G - NCS in the Foot Handout - Del Toro

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The document reviews electrodiagnostic assessment of lower-extremity entrapment neuropathies and reports a study comparing four techniques for recording the superficial fibular sensory nerve.<br /><br />Entrapment neuropathies result from focal mechanical compression, often causing segmental demyelination and, in severe cases, axonal loss. Nerve conduction studies (NCS) and needle electromyography (EMG) help identify the lesion’s location and severity by detecting slowed conduction, conduction block, reduced response amplitudes, or denervation.<br /><br />The workshop focuses particularly on common fibular nerve entrapment near the fibular head and posterior tibial nerve entrapment, including tarsal tunnel syndrome and compression of its plantar branches. It describes clinical patterns and NCS/EMG methods for these conditions, as well as less common neuropathies involving the deep and superficial fibular, interdigital, calcaneal, saphenous, and lateral femoral cutaneous nerves. Testing the appropriate sensory branches and recording muscles can help distinguish a focal lesion from more proximal nerve injury or generalized neuropathy.<br /><br />The later study compared the Spartan, two Izzo, and Daube techniques in 108 healthy volunteers (164 legs). A superficial fibular sensory response was obtained with at least one technique in every participant, and all four techniques produced a response in 95%. The Spartan method had the fewest absent responses and required the least stimulation, but generally produced the smallest amplitudes and longest latencies. The Daube method produced the largest amplitudes and shortest latencies but required the most stimulation. Despite statistical differences, the authors found little apparent clinical difference among techniques and considered all four reliable. Their findings support the value of superficial fibular sensory testing while underscoring that technique and normal anatomical variation can affect results.

Keywords

electrodiagnostic assessment

lower-extremity entrapment neuropathies

nerve conduction studies

ncs

needle electromyography

fibular nerve entrapment

tarsal tunnel syndrome

superficial fibular sensory nerve

segmental demyelination

axonal loss

sensory nerve recording