Figure 2. Representative example of mediolateral center of pressure (ML COP) displacement data (black solid line) and EMG amplitude of the tibialis anterior (gray solid line). Left axis represents ML COP displacement (m) and right axis represents the EMG amplitude of tibialis anterior (µV). Dotted vertical line represents EMG onset and dotted horizontal line represents baseline EMG mean + 2 standard deviations (SDs). Crossing point (CP) was considered as time 0 for EMG onset.