Effects of Seat Cushions on Human Vibration Response: Comparison of the Effectsof Whole-Body Vibration Exposure Between Females and Males

摘要

Discomfort, performance degradation, and increased health risk have beenassociated with prolonged exposures to vibration occurring in the operation of civilian and military vehicles. While an increasing number of females are selecting these occupations, the existing vibration standards and exposure limits are based on the male population. The objective of this study was to compare the biodynamic responses of females and males exposed to whole-body vibration. This final report includes the evaluation of resonance behaviors observed in the driving-point impedance, and in the chest, head, and spine transmissibilities at two acceleration levels for the rigid seat and with the use of seat cushions. While the primary resonance frequency (4-8 Hz) was not significantly affected, the peak impedance magnitudes, normalized for body weight, were significantly less for the females as compared to the males. The chest transmissibility results were more variable. There was a tendency for the horizontal chest motion to be lower and the vertical chest motion to be higher in the females as compared to the males. No clear trends were observed in the vertical head and spine transmissibility peaks. The results indicated that differences exist between females and males in the distribution of mass, stiffness and damping properties of specific anatomical structures contributing to the observed biodynamic responses.