Evaluation of Physical Load While Propelling Manual Wheelchair on Cross Slope Road and Wave Road

A vertical and cross slope, waves (unevenness) of a sidewalk are significant barrier to the mobility of wheelchair users. In Japan, the Law for Promoting Barrier-free Transport and Facilities for the Elderly and the Disabled specifies that a cross slope in sidewalk is recommended to be 1% gradient or less and it is allowed to be no greater than 2% when it is unavoidable. However, it is necessary to clarify the evidence for the guidelines how changes in a cross slope gradient affect the accessibility and the physical load of wheelchair users. And the objective assessment of barrier-free road construction to resolve wave-road should be investigated. The objective of this study was to experimentally clarify the relationship between the cross slope of an actual sidewalk environment and the physical load of wheelchair users by the oxygen uptake and the wheelchair propelling force. Our experimental results showed that the physical load of a wheelchair user in the 2% cross slope was not so strong statistically compared with the level surface. On the other hand, the required force of a downhill side handrim was significantly greater than that of an uphill side handrim. This unbalance of propelling force caused by the cross slope would increase the physical load of wheelchair users especially with hemiplegia. The reduced oxygen cost index indicated that the barrier-free road construction was effective for improving the accessibility of wheelchair. Based on these findings, we propose the evidence of a wheelchair user's physical load while propelling a cross slope and a wave-road.