Abstract
The response of the human body is investigated in this paper, whishes receiving the forced torsional oscillation from the bottom of his foot at the stand up posture or the bottom of his hip at the sit down posture. An experimental apparatus to give a forced oscillatory motion is developed, and the responses of the human body for young and aged peoples are measured. The amplitudes and phase lags of the parts of the human body by the torsional oscillation of the body are measured. From these results, the data of natural frequency of the torsional human body and the resonance phenomena of the human body are obtained. The investigated physical characteristics will be used as the index for the degree of aging, the hardness and the softness of a human body.
