Motor nerve conduction velocities in normal subjects with particular reference to the conduction in proximal and distal segments of median and ulnar nerve

Abstract

Motor nerve conduction velocity in the median, ulnar and anterior tibial nerves has been determined in 47 subjects, as well as the voltage of the evoked muscle action potential and the time interval between stimulus and the muscle action potential evoked from the distal electrode (Tables III–V). There was no significant difference in conduction velocity when stimulating with needle and surface electrodes. In the median and ulnar nerves, conduction velocity was significantly slower in the distal than in the proximal portion of the nerve, and the difference was not due solely to differences in temperature; it may be attributable to a decrease in fibre diameter from the proximal to the distal part of the nerve. The difference in conduction velocity between the right and left extremities in the same subject and the variation from person to person averaged 5–10%.