Precise measurement of nerve length across joints or irregular bony surfaces is critical for accurate determination of nerve conduction velocity (NCV). Recording techniques should be standardized to improve nerve conduction study reliability. The correlation between surface measurement of the tibial nerve segment through the tarsal tunnel, based on the distance between certain anatomical landmarks, and the true length of this segment, has not been previously studied. As a result, calculations of conduction velocity through this region may be inaccurate, leading to false interpretation. The purpose of this investigation was a) to determine, in a cadaver model, the ankle position where surface measurements of the tibial nerve segment through the tarsal tunnel most closely approximate the true length of the segment, and b) to then determine the reliability of conduction velocity measurements, in normal subjects, using this (and other) ankle positions.
