Figure 5.

Trend of changes and interaction effects of independent variables on the time-domain variables including (a) Mean RR, (b) SD of normal-to-normal intervals, (c) root mean square of the successive differences; and frequency-domain variables including (d) low frequency (LF) (n.u), (e) high frequency (HF) (n.u), and (f) LF/HF ratio across the rest and active periods *p value for the interaction between WBV and MWL **WBV: Whole-body vibration, LMWL: Low mental workload, HMWL: High mental workload, WBV.LMWL: Combined WBV and LMWL, and WBV.HMWL: Combined WBV and HMWL