Characterizing the rolling resistance force and deformation of in-wheel suspension systems in manual wheelchairs.

In-wheel suspension systems for manual wheelchairs offer a potential remedy for dissipating whole body vibrations; however, some users feel that they impede their propulsion efficiency. The purpose of this study was to compare Loopwheel Urban, a type of in-wheel suspension wheel to a carbon fiber wheel (Spinergy CLX) and standard spoked wheel to elucidate their comparative effects on rolling resistance force and axle deformation. Component-level drum-based testing revealed that the average rolling resistance force of the Loopwheels was 118% and 44% higher on linoleum and carpet surfaces than the standard wheels, respectively, and approximately 160% higher on carpet than the Spinergy CLX. Loopwheels demonstrated greater deformation (70 mm average across all loading conditions) compared to both standard and CLX wheels under static loading conditions. The increased rolling resistance force and deformation may help explain the perception among manual wheelchair users that Loopwheels impede their propulsion efficiency, despite their smoother ride and reduction of vibrations and shocks.