Propulsive Work Cost and Shoulder Movement during Lightweight and Ultra Lightweight Manual Wheelchair Propulsion in Pediatrics

Lightweight (K4) and ultra-lightweight (K5) wheelchairs are commonly used as mobility devices by pediatric manual wheelchair users. In this study, instrumented pushrims and wireless motion tracking were used to measure energy cost and shoulder flexion during manual wheelchair propulsion. Eight pediatric (age=1218 yrs) manual wheelchair users propelled a K4 and K5 wheelchair across a level tiled floor (“Tile”), over a polyfoam mat (“Mat”), and ascended an ADA approved (5 degree) ramp (“Ramp”). Compared with the K4 wheelchair (mean difference ± standard error), propulsion on the K5 wheelchair required less propulsive work per distance traveled (8.3±1.7 J∙m, p=0.002). Maximum shoulder flexion was greater (9.5±2.0°, p=0.003) when propelling the K5 wheelchair. This may be associated with a propulsion pattern that allows prolonged pushrim contact and contributes to the greater efficiency of propulsion observed. Propelling the wheelchair on Mat and Ramp was associated with higher propulsive work cost than on Tile. The study added to the body of evidence that, as well as weight differences, differences in setup and configuration options may contribute to the reduction in energy cost associated with propulsion using the K5 wheelchair.