The influence of temperature and excitation pattern on noninvasively detected conduction velocity in single motor units

Recordings of muscular conduction velocity (MCV) commonly show considerable long-term variabilities. As a possible reason for this, the influence of the temperature and excitation pattern was studied, using recordings from single motor units of superficial lower arm muscles. Single motor-unit action potentials were detected noninvasively by means of a spatially filtering multielectrode technique. Both parameters studied showed a strong influence; MCV varied with skin temperature by about 0.13 m/s/ degrees C, with firing rates from 0.028 to 0.064 m/s/s/sup -1/. Control of these parameters therefore could reduce problems of long-term reproducibility.<>