Abstract
Micro movement of the center in the brain and deformation of the skull due to hitting is calculated precisely without approximation from the acceleration data of 7 experiments of backwards falling down. The experiment has been done in JARI, and acceleration data are taken on the head, chest, pelvis and also neck (force) using a dummy robot, which simulates a human body. As a result, the whole picture of the falling and hitting becomes clear. It is shown that (1) the postures of falling are classified into 2 types, i.e., nearly same time hitting or delayed hitting of the pelvis. (2) Accelerations of the head are classified into 2parts, i.e., head's decelerating period and hitting on the floor. (3) The depth are from 2〜3 mm, which indicates the deformation of the skull is around 2mm. On the other hand, the height range from I cm to 7cm, depend on the falling posture. (4) The inclined angle of the face has been calculated.
