Cardiovascular responses induced by whole-body vibration training in patients with subacute stroke

Background Whole-body vibration(WBV) therapy has become a common treatment in rehabilitation of various patient populations. While it has been shown in healthy young adults that the oxygen consumption rate(VO_2)and heat rate(HR) are significantly increased when WBV is added to exercise. However, the cardiovascular response to WBV in patients with subacute stroke is unknown. The objective of this study was to determine the acute cardiovascular responses to WBV during the various exercises in different WBV conditions in patients with subacute stroke(onset less than 3 months). Methods A total of 54 subjects with subacute stroke performed six exercises while being exposed to 3 WBV conditions:(1) no WBV,(2) low WBV intensity [amplitude: 0.6 mm,frequency: 20 Hz, peak acceleration: 0.96 gravitational constant(G)], and(3) high WBV intensity(amplitude:0.44 mm, frequency: 30 Hz, peak acceleration: 1.61 G). The cardiovascular responses(HR and VO_2) were measured by a FitMateTMPro metabolic system during the 6 exercises. Two-way repeated measures ANOVA was used to compare the VO_2, and HR data across the different conditions. In addition, we calculated the rate pressure product(RPP) =(HR × systolic blood pressure)/100, for measuring the myocardial oxygen demand. Two-way ANOVA with repeated measures was used to compare the RPP data across the different test conditions. Results Exposure to WBV(high-and low-intensity protocols) significantly induced higher VO_2 by 0.35-1.07 mL·kg-1·min-1(P<0.001) and HR by 0.8-6.0 beats per minute(P<0.001) compared with the no WBV condition, regardless of the exercise performed. No significant difference in VO_2 and HR was found between the low-and high-intensity WBV protocols(P>0.05). For RPP, there was an overall significant effect between pre-and post-WBV(P<0.001). The main effect of WBV intensity(P=0.572), and intensity × time interaction effect(P=0.756), however,were not significant. Conclusions HR and VO_2 are increased significantly with addition of WBV training. The added low-and high-intensity WBV induce a similar increase in VO_2 and HR. RPP is similarly increased after exercise, regardless WBV is added or not[.S Chin J Cardiol 2019;20(1):15-24]