Development and calibration of drum-based rolling resistance testing machine for manual wheelchair components

BACKGROUND: Manual wheelchair users are at a high risk of repetitive strain injuries, carpal tunnel syndrome, and rotator cuff tears due to propelling their wheelchair for mobility. Rolling resistance (RR) is one of the key forces that leads to increased propulsion forces and risk of injuries. OBJECTIVE: To better understand the factors contributing to RR, we iteratively designed, developed, and validated a drum-based testing machine and test method. METHODS: As part of the validation of the system, we tested and compared 4 manual wheelchair wheels under a range of conditions including camber, toe in/out, tire pressure, surfaces, and speed. A treadmill was employed to simulate flat ground RR. RESULTS: A machine was effectively designed, developed, and tested to measure RR. Tire type, surfaces, and toe were found to be the largest contributors to RR. Comparison of the drum-based system to flat ground revealed that an offset can be used to calculate overground RR from drum measurements. CONCLUSIONS: Ongoing work includes performing a comprehensive analysis of the degree to which each factor contributes to RR of commonly used casters and rear-wheels so that the wheelchair sector can work to reduce RR and the associated risk of repetitive strain injuries.