Single pulse TMS-Active motor threshold (AMT) The measurement of AMT is similar with RMT measurement. Except that subject's feet were constrained by flexible weights placed over the dorsum of each foot to ensure isometric activation. The subject was given real time feedback of EMG on an oscilloscope to match a target contraction corresponding to 20% maximal voluntary isometric contractions (MVIC) for TA. The lowest intensity needed to elicit a MEP response of at least 100µV amplitude at the "hot spot" and that has been elicited in 50% of 8 successive trials will be recorded as AMT.