Northern Illinois University, DeKalb, IL, USA.
Shanghai University of Sport, Shanghai, China.
J Biomech. 2018 Aug 22;77:48-54. doi: 10.1016/j.jbiomech.2018.06.022. Epub 2018 Jun 23.
The purpose of this study was to examine the changes of lower extremity kinetics during walk-to-run (WR) transition and if the changes would follow a non-linear trend within the five strides before WR transition using a constant acceleration protocol.
Fourteen participants performed gait transition on the instrumented treadmill at a constant acceleration. Peak, time to peak, and movement and power of hip, knee and ankle joints were recorded and analyzed in sagittal plane for five strides before gait transition. Three Two-way MANOVA were employed to examine the differences of kinetic measures among the five strides. Univariate analysis and Post-Hoc Tukey's test would be applied if needed. Also, Post hoc polynomial trend analyses were used to examine the trend of the kinetic measures that significantly changed during the five strides.
Compared to the first four strides, significant differences were observed for peaks moments, joint powers, and time to peaks in the last stride before running at ankle, knee, and hip joints respectively. In general, the changes of kinetic variables were following a quadratic trend during the five strides before running.
Joint kinetic measures actively change in non-linear patterns during the five strides before running to prepare for the gait transition, indicating that the gait transition is an active reorganization rather than a passive reaction.
本研究旨在探讨在使用恒加速方案进行跑走转换时，下肢动力学在跑走转换前的五个步幅中是如何发生变化的，以及这些变化是否遵循非线性趋势。
14 名参与者在带仪器的跑步机上以恒加速进行步态转换。在矢状面记录并分析跑走转换前五个步幅的髋关节、膝关节和踝关节的峰值、峰值时间以及运动和功率。采用三因素二向方差分析比较五个步幅之间的动力学测量差异。如果需要，将进行单变量分析和事后 Tukey 检验。此外，还进行了多项式趋势分析，以检验五个步幅中显著变化的动力学测量的趋势。
与前四个步幅相比，跑走转换前最后一个步幅中踝关节、膝关节和髋关节的峰值时刻、关节功率和峰值时间差异显著。一般来说，在跑走转换前的五个步幅中，动力学变量的变化呈二次趋势。
在跑走转换前的五个步幅中，关节动力学测量值以非线性模式主动变化，为跑走转换做准备，这表明跑走转换是一种主动的重新组织，而不是被动的反应。
