期刊名称：The International Journal of Occupational and Environmental Medicine
印刷版ISSN：2008-6520
电子版ISSN：2008-6814
出版年度：2019
卷号：10
期号：4
页码：174-184
DOI：10.15171/ijoem.2019.1688
出版社：National Iranian Oil Company (NIOC) Health Organization
摘要：Background: Whole-body vibration (WBV) and mental workload (MWL) are common stressors
among drivers who attempt to control numerous variables while driving a car, bus, or
train.
Objective: To examine the individual and combined effects of the WBV and MWL on the
autonomic nervous system.
Methods: ECG of 24 healthy male students was recorded using NeXus-4 while performing
two difficulty levels of a computerized dual task and when they were exposing to WBV
(intensity 0.5 m/s2; frequency 3–20 Hz). Each condition was examined for 5 min individually
and combined. Inter-beat intervals were extracted from ECG records. The time-domain and
frequency-domain heart rate variability parameters were then extracted from the inter-beat
intervals data.
Results: A significant (p=0.008) increase was observed in the mean RR interval while the
participants were exposed to WBV; there was a significant (p=0.02) reduction in the mean
RR interval while the participants were performing the MWL. WBV (p=0.02) and MWL significantly
(p<0.001) increased the standard deviation of normal-to-normal intervals with a
moderate-to-large effect size. All active periods increased the low-frequency component and
low-frequency/high-frequency ratio. However, only the WBV significantly increased the highfrequency
component. A significant (p=0.01) interaction was observed between the WBV and
MWL on low-frequency component and low-frequency/high-frequency ratio.
Conclusion: Exposure to WBV and MWL can dysregulate the autonomic nervous system.
WBV stimulates both sympathetic and parasympathetic nervous system; MWL largely affects
sympathetic nervous system. Both variables imbalance the sympatho-vagal control as well.
其他摘要：Background: Whole-body vibration (WBV) and mental workload (MWL) are common stressors among drivers who attempt to control numerous variables while driving a car, bus, or train. Objective: To examine the individual and combined effects of the WBV and MWL on the autonomic nervous system. Methods: ECG of 24 healthy male students was recorded using NeXus-4 while performing two difficulty levels of a computerized dual task and when they were exposing to WBV (intensity 0.5 m/s 2 ; frequency 3–20 Hz). Each condition was examined for 5 min individually and combined. Inter-beat intervals were extracted from ECG records. The time-domain and frequency-domain heart rate variability parameters were then extracted from the inter-beat intervals data. Results: A significant (p=0.008) increase was observed in the mean RR interval while the participants were exposed to WBV; there was a significant (p=0.02) reduction in the mean RR interval while the participants were performing the MWL. WBV (p=0.02) and MWL significantly (p<0.001) increased the standard deviation of normal-to-normal intervals with a moderate-to-large effect size. All active periods increased the low-frequency component and low-frequency/high-frequency ratio. However, only the WBV significantly increased the highfrequency component. A significant (p=0.01) interaction was observed between the WBV and MWL on low-frequency component and low-frequency/high-frequency ratio. Conclusion: Exposure to WBV and MWL can dysregulate the autonomic nervous system. WBV stimulates both sympathetic and parasympathetic nervous system; MWL largely affects sympathetic nervous system. Both variables imbalance the sympatho-vagal control as well.
