Peter Harrison Centre for Disability Sport, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom.
Center for Human Movement Sciences, University Medical Center -Groningen, Netherlands.
Int J Sports Med. 2014 Mar;35(3):223-31. doi: 10.1055/s-0033-1345178. Epub 2013 Aug 14.
To compare the force application characteristics at various push frequencies of asynchronous (ASY) and synchronous (SYN) hand-rim propulsion, 8 able-bodied participants performed a separate sub-maximal exercise test on a wheelchair roller ergometer for each propulsion mode. Each test consisted of a series of 5, 4-min exercise blocks at 1.8 m · s-1 - initially at their freely chosen frequency (FCF), followed by four counter-balanced trials at 60, 80, 120 and 140% FCF. Kinetic data was obtained using a SMARTWheel, measuring forces and moments. The gross efficiency (GE) was determined as the ratio of external work done and the total energy expended. The ASY propulsion produced higher force measures for FRES, FTAN, rate of force development & FEF (P<0.05), while there was no difference in GE values (P=0.518). In pair-matched push frequencies (ASY80:SYN60, ASY100:SYN80, ASY120:SYN100 and ASY140:SYN120), ASY propulsion forces remained significantly higher (FRES, FTAN, rate of force development & FEF P<0.05), and there was no significant effect on GE (P=0.456). Both ASY and SYN propulsion demonstrate similar trends: changes in push frequency are accompanied by changes in absolute force even without changes in the gross pattern/trend of force application, FEF or GE. Matched push frequencies continue to produce significant differences in force measures but not GE. This suggests ASY propulsion is the predominant factor in force application differences. The ASY would appear to offer a kinetic disadvantage to SYN propulsion and no physiological advantage under current testing conditions.
为了比较异步（ASY）和同步（SYN）手轮推进在不同推动频率下的力应用特性，8 名健全参与者在轮椅滚轮测功计上分别进行了每种推进模式的独立亚最大运动测试。每个测试由一系列 5 个 4 分钟的运动块组成，速度为 1.8m/s，最初以他们自由选择的频率（FCF）进行，然后以 60、80、120 和 140%的 FCF 进行四个平衡试验。动力学数据是使用 SMARTWheel 获得的，用于测量力和力矩。总效率（GE）被确定为外部功与总能量消耗的比值。ASY 推进在 FRES、FTAN、力发展率和 FEF 方面产生了更高的力测量值（P<0.05），而 GE 值没有差异（P=0.518）。在配对匹配的推动频率（ASY80:SYN60、ASY100:SYN80、ASY120:SYN100 和 ASY140:SYN120）中，ASY 推进力仍然明显更高（FRES、FTAN、力发展率和 FEF P<0.05），而 GE 没有显著影响（P=0.456）。ASY 和 SYN 推进都表现出相似的趋势：即使没有改变力应用的总模式/趋势、FEF 或 GE，推动频率的变化也伴随着绝对力的变化。匹配的推动频率继续在力测量方面产生显著差异，但 GE 则没有。这表明 ASY 推进是力应用差异的主要因素。在当前的测试条件下，ASY 推进似乎对手轮推进具有动力学劣势，而没有生理优势。
