Oral Communication

Effect of Wheelchair Tire Types and Weight on Wheelchair Propulsion

Prof François ROUTHIERa, Mrs Brigitte GAGNONb, Mr Bruno LEMELINb, Prof Jean LEBLONDa

a Centre interdisciplinaire de recherche en réadaptation et intégration sociale (CIRRIS), Centre intégré universitaire de santé et de services sociaux de la Capitale nationale (CIUSS-CN), site IRDPQ, Québec, Canada, b Programme des aides techniques à la mobilité, Centre intégré universitaire de santé et de services sociaux de la Capitale nationale (CIUSS-CN), site IRDPQ, Québec, Canada

Background: The number of manual wheelchair users in USA was estimated to 2.7M individuals. Excessive loads to upper extremity joints are now a growing concern, causing possible loss of independence and increased healthcare cost. Consequently, there is a strong interest in clinical practice to reduce the mechanical effort to propel a wheelchair. The manual wheelchair tires being the interface between the wheelchair itself and the surface, their physical properties then become variables of great importance for which clinicians have few relevant data on to guide their interventions.

Objective: To determine the impact wheelchair propulsion of tire type, tire profile, wheelchair load, wheelchair type, tire pressure, and their interactions.

Method: To achieve our goal, we measured the distance traveled when a standardized push was applied by a mechanical propelling system for 2 wheelchair types (rigid frame and foldable), 3 urethane solid tire types with different profiles and 2 pneumatic tire types with different profiles at 100% and 75% of the manufacturer’s recommended pressure. This was done for all possible wheelchair configurations at 48.0, 75.4, 98.2 and 123.1 kg of mass added to the wheelchair.

Results: On average, solid tires ran 39% less distance (p<0.001), regardless of any other parameter. This effect remains clearly pronounced at all masses, although the relative impact increases with mass (31% at 48kg and 41% at 123.1kg, (p<0.0001)). Secondly, the foldable wheelchair showed up to 32% less rolling distance (p<0.001) at lower added mass than the rigid frame wheelchair. This advantage is negligible at 98.2kg and 123.1kg. Finally, tire pressure and tire profile were shown to be, at best, of higher order effects.

Discussion: Wheelchair users and clinicians have two options to reduce efforts related to wheelchair propulsion, by opting for pneumatic tires and/or rigid frame wheelchairs. Impact of those two parameters is less important for heavier wheelchair users.

Keywords : wheelchair, tire type, propulson