Abstract
In aging societies, the number of wheelchair users continues to rise, which in turn has increased the need for caregivers to provide assistance. However, research on the effects of cross slopes on wheelchair running trajectories has been lacking. We carried out experiments to measure the effects of cross slopes on the upper-limb muscle activity of caregivers, strength when gripping the wheelchair, and the wheelchair trajectory. To act as caregivers, 10 healthy participants were asked to drive wheelchairs carrying passengers along a 5-m-long experimental track. Three cross slopes were tested: 0%, 2%, and 5%. Increasing the cross slope significantly increased the activities of the forearm flexor muscles on the downslope side and extensor muscles on the upslope side, as well as the strength when gripping the wheelchair. In addition, the coefficients of variation for the wheelchair trajectory were significantly higher on the 5% cross slope than on the other cross slopes. These results suggest that wheelchair caregivers mainly use their forearms to handle cross slopes, especially as the cross slope increases. This study can help with training wheelchair caregivers to effectively handle cross slopes.
