Effects of Wheel and Tire Selection on High-Strength Lightweight Manual Wheelchair Propulsion Cost Using Robotic Propulsion

Abstract

<h3>Research Objectives</h3> To investigate the effects of wheel and tire selections on the propulsion characteristics of a high-strength lightweight manual wheelchair, a robotic propulsion device was deployed across a cohort of wheelchair configurations. <h3>Design</h3> This experimental study compared the mechanical behaviors of four wheelchair configurations with differing drive wheels and casters. <h3>Setting</h3> This study was conducted in a laboratory setting. Test surfaces (linoleum tile, low-pile carpet) represented common environments where high-strength lightweight wheelchairs are used. <h3>Participants</h3> No human subjects were used in this study. One high-strength lightweight wheelchair frame (Viper Plus GT, Drive Medical) was used for all four configurations. The baseline configuration reflected the default manufacturer configuration, comprising a solid mag drive wheel and solid 8"x1" caster. The other three configurations included Primo 6"x1.5" caster wheels and solid 24"x1-3/8" Primo XPress drive tires. <h3>Interventions</h3> The Anatomical Model Propulsion System (AMPS) robotic wheelchair tester propelled the chair using pre-generated straight and curvilinear maneuvers using repeatable and reliable cyclic torque profiles across tile and carpet. <h3>Main Outcome Measures</h3> The main outcome measure was propulsion cost, defined as the ratio of mechanical energy required to propel the wheelchair to the total distance traveled over-ground, reported in Joules per meter. In addition, the metric of 'value' – the retail cost of components in comparison to their relative impact on the energetic propulsion cost – was proposed for the first time in relation to high-strength lightweight wheelchair components. <h3>Results</h3> Results indicate significant reduction in propulsion cost across all maneuvers and surfaces with upgraded casters (<24%), drive wheel tires (<23%), or both (<41%). The total retail cost differential between the full sets of default components and upgraded components was $33 (USD). <h3>Conclusions</h3> This study demonstrated that better casters and drive wheel tires can improve the performance of high-strength lightweight wheelchairs and better meet the mobility needs of users. Furthermore, gaining knowledge of component-level energy losses could inform users, clinicians, and manufacturers on 'better' components that are available in each context of use. <h3>Author(s) Disclosures</h3> The authors do not have any conflicts to disclose.