*2.2.5. Statistical analysis*

The normality of F-wave data was not confirmed by using the Kolmogorov-Smirnov and Shapiro-Wilk tests. We used a nonparametric method in this research. The persistence, F/M amplitude ratio, and latency among three trials (rest, MI, post) under two MI conditions (50% MI and 100% MI conditions) were compared using the Friedman test and Scheffe's post hoc test.

We also calculated the relative value obtained by dividing F-wave data during MI under four MI conditions by that at rest. The relative values among two MI conditions were compared using the Wilcoxon signed rank test. We used SPSS statistics ver. 19 (IBM Corp., USA) for statistical analysis. The threshold for statistical significance was set to p = 0.05.
