Department of Exercise and Sport Sciences, United States.
Department of Biomedical Engineering, University of Rochester, United States.
J Biomech. 2019 Jun 11;90:119-122. doi: 10.1016/j.jbiomech.2019.04.023. Epub 2019 Apr 22.
The purpose of this study was to determine the validity of kinematic based initial contact (IC) and toe-off (TO) identification algorithms for rearfoot and non-rearfoot runners across a broad range of treadmill running speeds. 14 healthy active participants completed six 20-60 s treadmill running trials at 6 speeds: 2.24, 2.68, 3.13, 3.58, 4.02, and 4.48 ms. 3D kinematic data were collected for the last 20 s of each trial. Force plates (FP) were used as the gold standard to determine ICFP and TOFP for each step. Three algorithms for finding IC, IC, IC, IC, and one algorithm for finding toe off, TO, were chosen for analysis. Root mean square errors (RMSE) and difference scores with 95% confidence intervals were computed for IC, TO and stance time (ST). IC RMSE ranged from 0.175 to 0.219 s. ST RMSE ranged from 0.168 to 0.216 s. IC RMSE ranged from 0.105 to 0.131 s. ST RMSE ranged from 0.108 to 0.129 s. IC RMSE ranged 0.012 to 0.015 s. ST RMSE ranged 0.019 to 0.024 s. IC accuracy was inversely related to speed. IC corrected with a linear regression equation reduced differences to- 0.006 ± 0.012 s with 86% of foot strikes identified within 20 ms and 58% with 10 ms. TO RMSE ranged from 0.012 to 0.016 s. IC adjusted for speed and TO can be used to predict IC and TO within a broad range of treadmill running speeds (2.24-4.48 ms) and for rearfoot and non-rearfoot strikers.
本研究旨在确定基于运动学的初始接触（IC）和离地（TO）识别算法在广泛的跑步机跑步速度范围内对后足和非后足跑步者的有效性。14 名健康活跃的参与者在 6 种速度下完成了 6 次 20-60 秒的跑步机跑步试验：2.24、2.68、3.13、3.58、4.02 和 4.48 ms。收集了每个试验最后 20 秒的 3D 运动学数据。力板（FP）被用作确定每个步的 ICFP 和 TOFP 的金标准。选择了三种用于寻找 IC 的算法、IC、IC、IC、IC 和一种用于寻找离地的算法 TO，用于分析。计算了 IC、TO 和站立时间（ST）的均方根误差（RMSE）和 95%置信区间的差值得分。IC RMSE 范围为 0.175 至 0.219 s。ST RMSE 范围为 0.168 至 0.216 s。IC RMSE 范围为 0.105 至 0.131 s。ST RMSE 范围为 0.108 至 0.129 s。IC RMSE 范围为 0.012 至 0.015 s。ST RMSE 范围为 0.019 至 0.024 s。IC 准确性与速度成反比。通过线性回归方程校正的 IC 将差异减小到-0.006±0.012 s，86%的足触地时间在 20 ms 内，58%的足触地时间在 10 ms 内。TO RMSE 范围为 0.012 至 0.016 s。可以使用调整速度和 TO 的 IC 来预测跑步机跑步速度（2.24-4.48 ms）范围内的 IC 和 TO，以及后足和非后足跑步者的 IC 和 TO。
