Fig. 4. Box plot of changes in motor evoked potential amplitude from the abductor hallucis muscle after tetanic stimulation at stimulus intensities of 0, 5, 25, and 50 mA at %T1 of 5%. Motor evoked potentials were recorded at the ipsilateral side to tetanic stimulation. Tetanic stimulation (50 Hz, 50 mA) with a duration of 5 s was applied on the tibial nerve 1 s before transcranial stimulation. Motor evoked potential amplitudes were significantly higher with tetanic stimulation at stimulus intensities of 25 and 50 mA compared with control values (0 mA). *  P < 0.05  versus control (0 mA).