a Department of Sports and Exercise Medicine, Institute of Human Movement Science , University of Hamburg , Hamburg , Germany.
b Institute of Sport Science , Friedrich Schiller University Jena , Jena , Germany.
Eur J Sport Sci. 2019 May;19(4):413-421. doi: 10.1080/17461391.2018.1519040. Epub 2018 Sep 26.
In the analysis of human walking, the assessment of local dynamic stability (LDS) has been widely used to determine gait stability. To extend the concepts of LDS to the analysis of running biomechanics, this study aimed to compare LDS during exhaustive running between competitive and recreational runners. Fifteen recreational and fifteen competitive runners performed an exhaustive 5000 m run. Inertial measurement units at foot, pelvis, and thorax were used to determine local dynamic running stability as quantified by the largest Lyapunov exponent. In addition, we measured running velocity, lactate levels, perceived exertion, and foot strike patterns. LDS at the start, mid, and end of a 5000 m run was compared between the two groups by a two-way repeated-measures analysis of variance (ANOVA). Local dynamic stability increased during the run (thorax, pelvis) in both recreational and competitive runners (P = 0.006; P = 0.001). During the whole run, competitive runners showed a significantly higher LDS (P = 0.029) compared to recreational runners at the foot kinematics. In conclusion, exhaustive running can lead to improvements in LDS, indicating a higher local dynamic stability of the running technique with increasing exhaustion. Furthermore, LDS of the foot differs between the two groups at all measurement points. The results of this study show the value of determining LDS in athletes as it can give a better understanding into the biomechanics of running.
在人类行走分析中，局部动态稳定性（LDS）的评估已被广泛用于确定步态稳定性。为了将 LDS 的概念扩展到跑步生物力学分析中，本研究旨在比较竞技跑者和休闲跑者在全力跑步时的 LDS。15 名休闲跑者和 15 名竞技跑者进行了一次耗尽体力的 5000 米跑。使用脚部、骨盆和胸部的惯性测量单元来确定局部动态跑步稳定性，其通过最大 Lyapunov 指数来量化。此外，我们还测量了跑步速度、乳酸水平、感知用力和脚部着地模式。通过两因素重复测量方差分析（ANOVA）比较了两组在 5000 米跑的开始、中途和结束时的 LDS。结果发现，在整个跑步过程中，无论是竞技跑者还是休闲跑者，LDS 都有所增加（胸部、骨盆）（P=0.006；P=0.001）。与休闲跑者相比，在整个跑步过程中，竞技跑者的脚部运动学的 LDS 明显更高（P=0.029）。综上所述，全力跑步可以提高 LDS，这表明随着疲劳的增加，跑步技术的局部动态稳定性更高。此外，在所有测量点，两组之间的脚部 LDS 都存在差异。本研究的结果表明，在运动员中确定 LDS 的价值，因为它可以更好地理解跑步的生物力学。
