A physiological and biomechanical comparison of over-ground and treadmill during asynchronous wheelchair propulsion

Abstract

Two main modes of propulsion in manual wheelchair (MWC) are described in the literature: synchronous mode (Syn) in which arms are working together, and asynchronous mode (Asy) in which arms are working alternating. It has not yet been demonstrated that the propulsion technique used was identical on a treadmill and in the field, especially because of the movement of “steering” on the field during Asy propulsion. The aim of this study is to compare biomechanical and physiological responses of Asy during tests on the field vs. treadmill. Ten wheelchair basketball players performed 1 session of 4 minutes at 8 km.h −1 on the treadmill and 1 session on the field (‘figure 8’ tests). The MWC is equipped with an instrumented wheel allowing measuring temporal parameters: push time (PT), recovery time (RT) and cycle time (CT = PT + RT). Push frequency (PF), Rate of Rise (RoR), Fraction of Effective Force (FEF) and Rolling Resistance (RR) are also measured. Each subject is equipped with a K4, allowing to obtain the consumption of oxygen (VO 2 kg −1 ). The parameters collected are presented in Table 1 . Although the RR is higher for treadmill, Vo2.kg −1 and PT are superior on the over-ground. This can be explained by the steering on the field, which induces an increased use of the trunk muscles for stability. This could also explain lower PF and RoR. Therefore, field test is recommended to evaluate Asy propulsion.