Starting and stopping kinetics of a rear mounted power assist for manual wheelchairs

ABSTRACTA rear mounted, powered, drive wheel has been developed to assist with mobility for manual wheelchairs in indoor and outdoor modes. To start the wheel, users must initiate handrim propulsion with sufficient force to trigger the motor. To stop the indoor mode, users must apply a braking force through the handrims exceeding the device’s deceleration threshold. The objectives of this study were to compare 1) the minimum force required to start a wheelchair with and without the wheel, and 2) the distances and forces needed to stop a wheelchair at different treadmill speeds (3.5km/hr and 6.0km/hr) with and without the device. We used a crossover study design with 24 able-bodied persons. The main outcome measures were starting force (% Body Weight (BW)), single push speed, stopping distance, and stopping force (%BW). Participants did not have significantly increased starting force or single push speed using the drive. Participants had significantly shorter stopping distance (P = 0.045) (8–11%) and reduc...