Fig. 7

Statistical charts of tremor frequency in 8 subjects. The frequency of the peak value between 2 to 7 Hz of the PSD of each time period was denoted as tremor frequency. The average tremor frequencies of three time periods were calculated from all trials, DOFs and EMGs of one subject. The Wilcoxon signed-rank test was employed to show the differences of tremor frequency between the time periods. *0.01 < p < 0.05; **p < 0.01