Study of the Effects of Whole-Body Vibration in the Low Frequency Range

The current ISO criterion curve (ISO 2631) evaluated a psychological method on comfortable and uncomfortable feelings. To this end, it was necessary to have data for both the physiological reaction and the psychological evaluation of humans in the low frequency range. The purpose of this study is to clarify the physiological and psychological effects of low frequency horizontal whole body vibration. Heart rate, respiratory rate, salivation and subjective symptoms were measured before starting and 21-mins after starting at frequencies ranging from 0.01 to 0.8 Hz. The results were as follows: Changes in the autonomic nervous system were observed, and the system tended to change from the state of predominance of the parasympathetic nervous system to that of the sympathetic nervous system when the frequency values outside the range 0.4 to 0.8 Hz, during 21-min. Throughout all the process of the measurements, it is hypothescied that these variations have been caused by the physiological and psychological changes due to the frequency, delay time and acceleration based on the whole-body vibration.