Normalized H-wave amplitude (A), normalized soleus EMG amplitude (B), and normalized ratio of H-wave amplitude to background EMG (C). Amplitudes of H-wave and soleus rectified EMG were first normalized to the peak-to-peak amplitude of M
of that time epoch. To reduce the inter-subject variability, we then normalized the amplitudes in each condition to the values of the first unpowered condition. Thus, the normalized data in the first unpowered condition were 1.0 (100%) for the three epochs.