Background: This study assesses curved track effects on fatigue symmetry and lower limb muscle activity while taking maximum velocity running kinematics into account. Methods: Polish master class athletes were examined (age 24.6 ± 3.67 years, bm 78.9 ± 6.02 kg, and bh 186.1 ± 6.63 cm). The measurements were made on a 400 m synthetic surface athletics track. The DelSys 16 channel system was employed to measure the activity of the right and left leg muscles. The kinematic variables of the run were obtained using a 3-axis accelerometer built into the recorder. Results: The study revealed curved track effects on asymmetric muscle activity and running kinematics in the first two sections of the run. On the first curve, the symmetry index (SI) was 8.1%, while in on straight, it was 11.5%. Moreover, significantly lower values of the fatigue index b were found for the right limb (F_(3.36) = 6.504; p = 0.0152). Conclusions: A reduction of asymmetric muscle activity is linked with compensatory muscle stimulation triggered by the nervous system and with adjusting running kinematics to changing external conditions. Therefore, the main focus further research should be on the optimal interaction between stride length and frequency in relation to the muscle activity corresponding to the track geometry.

中文翻译：

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基于肌电信号的400m跑下肢肌肉疲劳的对称性

背景：本研究评估了弯曲轨道对疲劳对称性和下肢肌肉活动的影响，同时考虑了最大速度跑步运动学。方法：对波兰大师级运动员进行了检查（年龄 24.6 ± 3.67 岁，体重 78.9 ± 6.02 kg，体重 186.1 ± 6.63 cm）。测量是在 400 m 的合成表面田径跑道上进行的。DelSys 16 通道系统用于测量左右腿肌肉的活动。使用内置于记录器中的 3 轴加速度计获得运行的运动学变量。结果：该研究揭示了在跑步的前两个部分，弯曲跑道对不对称肌肉活动和跑步运动学的影响。在第一条曲线上，对称指数 (SI) 为 8.1%，而在直线上为 11.5%。此外，疲劳指数的值显着降低b为右肢（F _(3.36) = 6.504；p = 0.0152）。结论：不对称肌肉活动的减少与神经系统触发的代偿性肌肉刺激以及根据不断变化的外部条件调整跑步运动有关。因此，进一步研究的主要重点应该是步幅长度和频率之间的最佳相互作用与对应于轨道几何形状的肌肉活动。