Mohr Maurice, von Tscharner Vinzenz, Nigg Sandro, Nigg Benno M
Department of Sport Science, University of Innsbruck, Innsbruck 6020, Austria; Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada.
Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada.
J Sport Health Sci. 2022 May;11(3):309-318. doi: 10.1016/j.jshs.2021.01.003. Epub 2021 Jan 13.
This study aimed to investigate whether there is a systematic change of leg muscle activity, as quantified by surface electromyography (EMG), throughout a standard running footwear assessment protocol at a predetermined running speed.
Thirty-one physically active adults (15 females and 16 males) completed 5 testing rounds consisting of overground running trials at a speed of 3.5 m/s. The level of muscle activity from 6 major leg muscles was recorded using surface EMG. The variables assessed were the EMG total intensity as a function of time and the cumulative EMG overall intensity. Systematic effects of the chronological testing round (independent variable) on the normalized EMG overall intensity (dependent variable) were examined using Friedman analysis of variates and post hoc pairwise Wilcoxon signed-rank tests (α = 0.05).
There was a systematic reduction in overall EMG intensity for all 6 muscles over the time course of the running protocol (p < 0.001) until the fourth testing round when EMG intensities reached a steady state. The one exception was the biceps femoris muscle, which showed a significant reduction of EMG intensity during the stance phase (p < 0.001) but not the swing phase (p = 0.16).
While running at a predetermined speed, the neuromuscular system undergoes an adaptation process characterized by a progressive reduction in the activity level of major leg muscles. This process may represent an optimization strategy of the neuromuscular system towards a more energetically efficient running style. Future running protocols should include a familiarization period of at least 7 min or 600 strides of running at the predetermined speed.
本研究旨在调查在以预定跑步速度进行的标准跑鞋评估方案中，通过表面肌电图（EMG）量化的腿部肌肉活动是否存在系统性变化。
31名身体活跃的成年人（15名女性和16名男性）完成了5轮测试，包括以3.5米/秒的速度进行的地面跑步试验。使用表面肌电图记录6条主要腿部肌肉的肌肉活动水平。评估的变量是作为时间函数的EMG总强度和累积EMG总体强度。使用弗里德曼变量分析和事后成对威尔科克森符号秩检验（α = 0.05）检查按时间顺序排列的测试轮次（自变量）对标准化EMG总体强度（因变量）的系统性影响。
在跑步方案的时间过程中，所有6条肌肉的EMG总体强度都有系统性降低（p < 0.001），直到第四轮测试时EMG强度达到稳定状态。唯一的例外是股二头肌，其在站立期EMG强度显著降低（p < 0.001），但在摆动期没有降低（p = 0.16）。
在以预定速度跑步时，神经肌肉系统会经历一个适应过程，其特征是主要腿部肌肉的活动水平逐渐降低。这个过程可能代表了神经肌肉系统朝着更节能的跑步方式的优化策略。未来的跑步方案应包括至少7分钟或600步以预定速度跑步的适应期。
