Lloyd R, Cooke C B
School of Sciences, University of Sunderland, Sunderland, UK.
Ergonomics. 2000 Sep;43(9):1331-41. doi: 10.1080/001401300421770.
This study assessed changes in kinetics from unloaded walking associated with load carriage using both a traditional and a new rucksack design that incorporates front balance pockets (AARN). Nine subjects walked at 3(+/-0.05) km x h(-1) over a force plate unloaded and carrying 25.6 kg in each of the rucksacks. The order of trials was randomized and speed-controlled by use of photoelectric cells and a millisecond timer. Anteroposterior and vertical ground reaction forces were analyzed using repeated measures ANCOVA (speed covariate). There was a trend for the AARN pack to elicit a shorter support time than the traditional pack, 1.025+/-0.049 versus 1.037+/-0.06 s (p = 0.056), while the unloaded condition produced the shortest support time, 1.016+/-0.04 s. Both braking and propulsive forces for the rucksacks were significantly greater than for unloaded walking. While there was no significant difference between the packs for the braking force, the AARN pack produced a significantly lower (p<0.05) propulsive force than the traditional rucksack, 0.79+/-0.2 versus 0.94+/-0.16 N x kg bodyweight(-1). Both rucksacks produced significantly greater (p<0.001) vertical force peaks than unloaded walking, the increases being proportional to the increase in system weight. These findings indicate that there may be some advantage in terms of propulsive force production for the front/back system.
本研究使用传统背包和一种带有前平衡口袋（AARN）的新型背包设计，评估了与背负负荷相关的无负荷行走时的动力学变化。九名受试者在测力板上以3（±0.05）km·h⁻¹的速度行走，分别在无负荷状态下以及背负每个重25.6千克的背包时进行测试。试验顺序是随机的，并通过光电管和毫秒定时器来控制速度。使用重复测量协方差分析（速度作为协变量）对前后和垂直地面反作用力进行分析。AARN背包有产生比传统背包更短支撑时间的趋势，分别为1.025±0.049秒和1.037±0.06秒（p = 0.056），而无负荷状态下支撑时间最短，为1.016±0.04秒。两种背包的制动力和推进力都显著大于无负荷行走时。虽然两种背包的制动力没有显著差异，但AARN背包产生的推进力显著低于传统背包（p<0.05），分别为0.79±0.2与0.94±0.16N·kg体重⁻¹。两种背包产生的垂直力峰值都显著大于无负荷行走时，增加量与系统重量的增加成正比。这些发现表明，前后系统在推进力产生方面可能具有一些优势。
