ABSTRACT
Widespread advance of new technologies, especially in transportation industry poses human encounter with whole-body vibration. Besides biomechanical and physiological effects of whole-body vibration, it also has emotional and cognitive effects. Mental fatigue is an important factor in driving that can decrease driver's performance. Therefore, the aim of this study was to determine the effect of whole-body vibration on vehicle driver's reaction time, mental and physiological workload. In this laboratory and interventional study, 40 volunteers from university students [all male with average age 23.07 +/- 2.5 and average BMI 22.8 +/- 1.07] randomly selected. This study consists of three stages. In these stages, participants were encountered with three levels of whole-body vibration [low, average, high], 3-7 Hertz frequency in vertical direction that produced with a vibration simulator. In every stage, participants performed a selective visual reaction time test, and correct and incorrect answers recorded. During performing the test, the average heart rate as an indicator of physiological workload was recorded with sport tester at each stage. At the last of each stage, there was 5-minute break, and we wanted them to fill NASA TLX questionnaire. Statistical analysis was performed using ANOVA test. The results of this study showed that the vibration intensity has the significant effect on average heart rate [P=0.000], mental workload [P=0.01], average of correct answers [P=0.01] and incorrect answers [P=0.01], But it has no effect on reaction time. The results showed whole-body vibration decreases mental performance and increases physiological fatigue. So control of whole-body vibration in high intensity has an important role in promotion of safety and convenience