Report

Efficiency of hand-rim wheelchair-propulsion

Wheelchair propulsion is relatively inefficient physiologically in comparison to other forms of locomotion such as running, cycling and handcycling.

Lead academic:
Professor Vicky Tolfrey
Funder:
The Peter Harrison Foundation

Except for handcycling, these modalities tend to be asynchronous (ASY) in their nature prompting the question as to whether wheelchair propulsion could be better if also performed asynchronously. In light of the interests from wheelchair sports and daily wheelchair users which are beginning to utilise an ASY movement pattern makes investigation of such a technique appropriate.

Therefore, these studies explored whether an ASY propulsion mode can be more efficient than a synchronous (SYN) propulsion mode.

Methods

  • To help answer this question, a number of experimental studies compared SYN and ASY propulsion modes in wheelchair games players and novice able-bodied participants.
  • Gross mechanical efficiency (GE) measures, physiological variables, psycho-physiological markers (RPE), propulsion practice and kinetic measures were measured to help address the research question during wheelchair propulsion on a wheelchair ergometer.
  • The overall hypothesis was that ‘ASY propulsion will improve the GE of wheelchair propulsion and be more advantageous compared to that of the traditional SYN propulsion’.

Main findings and implications

  • Push (arm) frequency is the predominant component of push strategy selection for individuals during hand-rim wheelchair propulsion.
  • Practice is a key element in improving GE and is particularly advantageous at unpaced freely chosen frequency (FCF) and paced (80% of FCF).
  • The feedback mechanism of pacing via the use of audio cues can assist with the practice and learning of the complex task of hand-rim wheelchair propulsion. This would assist the process by encouraging individuals to meet requirements for a more optimum GE.
  • Awareness of the rate of rise in hand-rim forces during different push strategies and the possible link with risk of injury.
  • Propulsion practice should not be aimed at the optimisation of propulsion force because this may be less efficient and more straining for individuals.
  • Push strategy choices can reduce physiological demands and changes to push strategy are easy to manipulate and implement.

Reference

Lenton, J.P., Fowler, N.E., Woude, van der L.H.V., Nicholson, G., Tolfrey, K. and Goosey-Tolfrey, V.L. (2013). Synchronous hand-rim propulsion forces and efficiency. International Journal of Sports Medicine. 34(2):158-164. DOI: 10.1055/s-0032-1311650