Examination of the Impact of Differences in Restraint Conditions and Stimulus Intensity on the Fall Avoidance Strategy During a Slip Fall

In this paper, we analyze fall avoidance strategies with experiments during the applied stimulation of the slipping fall. The objective is a verification whether a fall avoidance movement in a single subject will be changed or not changed by the difference of experimental conditions. There are two conditions in these experiments. One is restrained of subject's movement by a string. The other is increased a intensity of the applying stimulus in experiments. In restrained the condition, caused by limited lowly angle of the shoulder joint and the hip joint, a subject cannot swing a upper limb and a lower limb like a usual in the forward and backward direction. In the condition of the stimulus intensity, caused by control an acceleration of one side belt in split-belt treadmill, a stimulus intensity can be increased or decreased. As a result, in restrained the condition caused by limited lowly angle of the shoulder joint and the hip joint, one subject had fallen in the first half of the trial, but could avoid fall in the latter half of the trial. Therefore, it was found that even if the subject had fallen initially in a condition, the subject may have changed the fall avoidance strategy finally in order to avoid a fall in the same condition.