Wheelchair tyre pressure: a community survey and an investigation of effect of low pressure on physiological energy expenditure during self- propulsion

Abstract

Wheelchairs issued on prescription are of a generic design and only accommodate individual requirements to a limited extent. Basic maintenance, for example use of the recommended tyre pressure to minimize rolling resistance, may therefore help reduce the energy expenditure of propulsion for patients issued with these standard wheelchairs. In a community survey of 145 wheelchairs (99 self-propulsion and 46 attendant-propulsion models) we found that only 4% of the self-propulsion wheelchairs had the recommended tyre pressure. Overall, 14% had pressures ≤ 5 pounds per square inch (psi) and a further 37% were between six and 15 psi. In 10 able-bodied subjects, we also found a significant rise (p < 0.01) of approximately 20% in the physiological energy expenditure of self-propelling a standard wheelchair, as assessed by minute ventilation, gas exchange and heart rate, when tyre pressure was reduced from 45 psi to ≤ 5 psi. Introduction of solid synthetic tyres, therefore, will have considerable advantages for patients who do not maintain even the lowest pressure needed to minimize energy expenditure. Use of this material for tyres of self-propulsion wheelchairs is also highly desirable.