Department of Sport and Leisure Studies, Keimyung University, Daegu 42601, Korea.
Department of Physical Education, Seoul National University, Seoul 08826, Korea.
Int J Environ Res Public Health. 2022 Aug 5;19(15):9656. doi: 10.3390/ijerph19159656.
We investigated the effect of prolonged running on joint kinematics and its association with stride complexity between novice and elite runners. Ten elite marathoners and eleven healthy individuals took part in a 20 min submaximal prolonged running experiment at their preferred running speed (PRS). A three-dimensional motion capture system was utilized to capture and calculate the alpha exponent, stride-to-stride fluctuations (SSFs), and stride-to-stride variability (SSV) of spatiotemporal parameters and joint kinematics. In the results, the elite athletes ran at a considerably higher PRS than the novice runners, yet no significant differences were found in respiratory exchange ratio with increasing time intervals. For the spatiotemporal parameters, we observed a significant increase in the step width and length variability in novice runners with increasing time-interval (p < 0.05). However, we did not observe any differences in the alpha exponent of spatiotemporal parameters. Significant differences in SSF of joint kinematics were observed, particularly in the sagittal plane for ankle, knee, and hip at heel strike (p < 0.05). While in mid-stance, time-interval differences were observed in novices who ran with a lower knee flexion angle (p < 0.05). During toe-off, significantly higher SSV was observed, particularly in the hip and ankle for novices (p < 0.05). The correlation analysis of joint SSV revealed a distinct negative relationship with the alpha exponent of step-length and step-width for elite runners, while, for novices, a positive relation was observed only for the alpha exponent of step-width. In conclusion, our study shows that increased step-width variability seen in novices could be a compensatory mechanism to maintain performance and mitigate the loss of stability. On the other hand, elite runners showed a training-induced effective modulation of lower-limb kinematics to improve their running performance.
我们研究了长时间跑步对关节运动学的影响及其与新手和精英跑者步幅复杂性的关系。十名精英马拉松运动员和十一名健康个体以他们的个人最佳跑步速度（PRS）参与了 20 分钟的亚最大耐力跑步实验。利用三维运动捕捉系统来捕捉和计算时空参数和关节运动学的 alpha 指数、步长到步长波动（SSF）和步长到步长变异性（SSV）。结果表明，精英运动员的 PRS 明显高于新手跑者，但随着时间间隔的增加，呼吸交换率没有显著差异。对于时空参数，我们观察到新手跑者的步宽和步长变异性随着时间间隔的增加而显著增加（p<0.05）。然而，我们没有观察到时空参数 alpha 指数的差异。关节运动学的 SSF 存在显著差异，尤其是在脚跟触地时的矢状面，脚踝、膝盖和臀部（p<0.05）。而在中间站立阶段，观察到膝屈角较低的新手跑者的时间间隔差异（p<0.05）。在离地阶段，明显观察到新手的 SSV 更高，尤其是脚踝和髋关节（p<0.05）。关节 SSV 的相关分析表明，与精英跑者的步长和步宽 alpha 指数呈明显负相关，而新手跑者仅观察到步宽 alpha 指数呈正相关。总之，我们的研究表明，新手步宽变异性的增加可能是一种补偿机制，以维持性能并减轻稳定性的损失。另一方面，精英跑者表现出下肢运动学的训练诱导的有效调节，以提高他们的跑步表现。
