BACKGROUND Recently, the use of treadmills for walking and running has increased due to lifestyle changes. However, biomechanical differences in coordination between running on a treadmill or overground have not been adequately addressed. RESEARCH QUESTION The purpose of this study was to compare coordination and its variability in lower limb segments during treadmill and overground running at different speeds. METHODS Twenty physically active university undergraduate students participated in this study. Each participant ran trials for both overground and treadmill running at slow and fast speeds. Three-dimensional kinematic data of the lower limb segments were captured. The continuous relative phase (CRP) was used to compute coordination and its variability (VCRP) for foot, shank, and thigh segments of the dominant side of the participants. RESULTS A vector analysis using statistical parametric mapping (SPM) revealed that there were statistically significant differences in the calculated CRPs for treadmill and overground running in the stance phase of running and for different running speeds in the late stance and swing phases. However, the VCRPs calculated for the two locations and speeds did not exhibit any statistically significant differences. CONCLUSION The findings of this study suggest differences in segment coupling between treadmill and overground running may affect lower extremity biomechanics. In addition, changes in the coupling patterns for different running speeds suggest that segment coordination is not stable in the range of training speeds used by runners. Finally, the lack of differences in the variability of segment couplings during treadmill and overground conditions at different speeds potentially demonstrates similar dynamic neuromuscular control and degrees of freedom at these different running locations and speeds.

中文翻译：

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在跑步机和地面上以不同速度跑步时，下肢各部分的协调性及其可变性的比较。

背景技术近来，由于生活方式的改变，跑步机在步行和跑步中的使用已经增加。但是，在跑步机上或在地面上跑步之间协调方面的生物力学差异尚未得到充分解决。研究问题这项研究的目的是比较跑步机和地面以不同速度跑步时下肢节段的协调性及其可变性。方法20名体育锻炼的大学本科生参加了这项研究。每个参与者都针对慢速和高速跑步的地面和跑步机进行了试验。捕获下肢节段的三维运动学数据。连续相对阶段（CRP）用于计算参与者占主导地位的一侧的脚，小腿和大腿部分的协调性及其变异性（VCRP）。结果使用统计参数映射（SPM）进行的矢量分析显示，跑步状态和跑步状态下跑步机和地面跑步的计算出的CRP有统计学上的显着差异，后期姿态和挥杆阶段的跑步速度不同。但是，针对这两个位置和速度计算出的VCRP并没有显示出统计学上的显着差异。结论这项研究的结果表明，跑步机和地面跑步之间的节段耦合差异可能会影响下肢的生物力学。另外，针对不同跑步速度的耦合模式的变化表明，分段协调在跑步者使用的训练速度范围内不稳定。最后，