Effect of Spinal Curvature on Cardiorespiratory Responses in Wheelchair Driving

[Purpose] This study compared cardiorespiratory responses during wheelchair driving under two different conditions of spinal curvature. [Subjects] Sixteen healthy men who provided their written informed consent. [Methods] We investigated respiratory rate (RR), tidal volume (TV), minute ventilation volume (VE), movements of the thoracic trunk and abdomen at maximal respiration, and heart rate (HR) at rest and during wheelchair driving 20 seconds after the start of driving (phase I), under two spinal curvature conditions. [Results] RR of wheelchair driving was significantly increased by enhanced spinal curvature, whereas TV and HR during wheelchair driving showed no significant changes. TV and VE were significantly decreased by enhanced spinal curvature in phase 1. In addition, O2 debt was significantly increased by enhanced spinal curvature. [Conclusion] We conclude that in wheelchair driving, enhanced spinal curvature increases O2 debt, due to reduced TV and VE responses in phase I.