Accelerations experienced by wheelchair users with spinalcord injury in a moving van

Abstract

Wheelchair users who drive must overcome the dynamic vehicle environment to maintain stability. Proper stability might increase functional ability and improve the driving ability of wheelchair users. This project investigated a dynamic environment by measuring the accelerations experienced by individuals with spinal cord injury during vehicle acceleration, deceleration and curve maneuvers. RMS accelerations along three axes were measured at the sternum of the subjects and the floor of the vehicle. The subjects sat both passively and while grasping a structure to simulate gripping driving controls. Trunk stability was measured by contact switches secured to the wheelchair backrest. Seated stability was greater when the subjects grasped the structure. Stability was also positively correlated with increasing the rate of change of velocity (vehicle accelerations) during decelerations and curves and negatively correlated during acceleration maneuvers. Vehicle and subject responses varied greatly. This variability underscores the complexity involved when researching the functional abilities of the spinal cord injured population within a complex dynamic environment.