Abstract
The present study intended to find out the perceptible threshold level of human body to a mechanical shock, which has not yet been fully investigated. The subjects for this study were seventy males, aged from 18 to 55. They who sat down straight and unbindingly, were impacted from +Gx and -Gx. The movement of hammer-heads used here was fixed from the region impacted to there. The regions observed include forehead, para-sternal thorax, interscapular thorax and the right gluteal region. The perceptible threshold level at the forehead had the lowest velocity and the largest acceleration. On the contrary, that at the gluteal region had the largest velocity and the lowest acceleration. The impact force at the threshold level showed similar value at each region. The mean value of the impact characteristics (G·S), which is the product of acceleration and its duration, was 0.030 G·S at the forehead and that was 0.063 G·S at the gluteal region. The mean threshold level of all regions in terms of acceleration were 0.610G at 5Hz, 0.855G at 10Hz and 1.153G at 20Hz.
