Abstract
In our daily life, we can keep standing without any consciousness, even when we are subjected to the base excitation such as earthquakes or train motions. However, from the view point of dynamic behaviors, the maintenance mechanism of standing state is not fully clarified. Especially for the elderly people, the risk for overturning increases due to decreasing muscle forces. And consequently, overturning will sometimes cause some difficulties in walking. Thus, it is very important to study the dynamic behaviors and the stability of the human in the upright position subjected to base excitations. In this study, the maintenance mechanism of standing state is investigated using a simplified dynamic human model. And the differences of the vibration response between the young and elderly people are studied. As a result, it is clarified that for elderly people, muscular loads on the waist and knee tend to increase, while for young people, those on the ankle tend to increase.
