Comparison of conduction velocities of nerve fibers to smaller and larger muscles in rats.

The aim of this study was to compare conduction velocities of motor fibers to smaller and larger muscles and to investigate the advantages and disadvantages of recordings from the gastrocnemius muscle with surface electrodes over the recordings from small foot muscles (interosseous muscles) with needle electrodes in rats. Surface and needle recordings are suitable in measuring the motor conduction velocity of the sciatic (tibial) nerve. It should be noted that the motor velocity measured from the gastrocnemius muscle is higher than the motor velocity elicited from small foot muscles. Surface recordings provide information on the amplitude and duration of M responses.