Abstract
The purpose of this study was to investigate the effects of dimensions of stairs and handrail on the low back load during ascending and descending staircases. We measured the low back joint moment as one of the objective representatives of the low back load, using force plates and three-dimensional motion analysis system on eight healthy elderly men. The subjects were asked to ascend and descend six staircases, two of them with handrail, staircases were made according to the upper limit values of the specifications of the Building Standards Act of Japan and recommended values for elder people by the Ministry of Land, Infrastructure and Transport in Japan. Increase in riser dimensions resulted in increased low back joint moments during ascending stairs while no change was observed with increase in tread dimensions. However, during descending the low back joint moment was affected by riser and the tread dimensions. It was found that the low back joint moment was considerably minimized when subjects ascended stairs with handrail.
