Optimal distance for segmental nerve conduction studies revisited.

In 1972, Maynard and Stolov showed that the experimental error in calculating nerve conduction velocity (NCV) depends on errors of latency and distance measurements. Their data suggested that a minimum distance of 10 cm should be used when calculating NCV because of an increase in error >/= 25% at shorter distances. The object of this study was to reestablish the minimum distance using current technology.

Changes in nerve conduction velocity across the elbow due to experimental error.

One diagnostic criterion for ulnar nerve mononeuropathy at the elbow (UNE) is a decrease in across-elbow nerve conduction velocity (NCV) > 10 m/s compared to the forearm segment. Distance and latency measurement errors are an inherent part of NCV calculations. Twenty electromyographers measured the latencies of stored ulnar compound muscle action potentials and measured the forearm and across-elbow distances along the ulnar nerve.