University of Twente, Faculty of Electrical Engineering, Mathematics and Computer Science, Enschede, The Netherlands; Roessingh Research and Development, Enschede, The Netherlands.
Roessingh Research and Development, Enschede, The Netherlands; University of Twente, Faculty of Electrical Engineering, Mathematics and Computer Science, Enschede, The Netherlands.
J Biomech. 2021 May 24;121:110419. doi: 10.1016/j.jbiomech.2021.110419. Epub 2021 Apr 9.
In running assessments, biomechanics of the stance phase are often measured to understand external loads applied to the body. Identifying time of initial foot contact can be challenging in runners with different strike patterns. Peak downward velocity of the pelvis (PDVP) has been validated in a laboratory setting to detect initial contact. Inertial measurement units (IMUs) allow measurements of kinematic variables outside laboratory settings. The aim of this study was to validate the PDVP method using an inertial and optical motion capture system to detect initial contact at different speeds and foot strike patterns compared to the force sensing criterion. Twenty healthy runners ran for two minutes at 11, 13, and 15 km/h on a force-instrumented treadmill. 3D kinematics were obtained from an optical motion capture system and an 8-sensor inertial system. A generalized estimating equation showed no effect of footstrike pattern on the time difference (offset) between initial contact based on an inertial or optical system and the force sensing criterion. There was a significant main effect of speed on offset, in which offsets decreased with higher speeds. There was no interaction effect of speed and foot strike pattern on the offsets. Offsets ranged from 21.7 ± 0.2 ms for subjects running at 15 km/h (inertial versus force sensing criterion) to 27.2 ± 0.1 ms for subjects running at 11 km/h (optical versus force sensing criterion). These findings support the validity of the PDVP method obtained from optical and inertial systems to detect initial contact in different footstrike patterns and at different running speeds.
在进行评估时，通常会测量站立阶段的生物力学，以了解施加在身体上的外力。在具有不同着地方式的跑者中，确定初始触地时间可能具有挑战性。在实验室环境中，已验证骨盆向下速度峰值（PDVP）可用于检测初始接触。惯性测量单元（IMU）允许在实验室环境之外测量运动学变量。本研究的目的是使用惯性和光学运动捕捉系统验证 PDVP 方法，以检测不同速度和不同足着地方式下的初始接触，与力感测标准相比。20 名健康跑者在测力跑步机上以 11、13 和 15 km/h 的速度分别进行两分钟的跑步。从光学运动捕捉系统和 8 传感器惯性系统获得 3D 运动学数据。广义估计方程显示，足着地方式对基于惯性或光学系统与力感测标准的初始接触的时间差（偏移量）没有影响。速度对偏移量有显著的主要影响，随着速度的增加，偏移量减小。速度和足着地方式对偏移量没有交互作用。偏移量的范围为 21.7±0.2ms（15km/h 时的惯性与力感测标准相比）至 27.2±0.1ms（11km/h 时的光学与力感测标准相比）。这些发现支持从光学和惯性系统获得的 PDVP 方法检测不同足着地方式和不同跑步速度下的初始接触的有效性。
