Mechanical and Materials Engineering, Queen's University, Canada.
Mechanical and Materials Engineering, Queen's University, Canada.
J Biomech. 2021 May 24;121:110422. doi: 10.1016/j.jbiomech.2021.110422. Epub 2021 Apr 8.
The clinical uptake and influence of gait analysis has been hindered by inherent limitations of marker-based motion capture systems, which have long been the standard method for the collection of gait data including kinematics. Markerless motion capture offers an alternative method for the collection of gait kinematics that presents several practical benefits over marker-based systems. This work aimed to determine the reliability of lower limb gait kinematics from video based markerless motion capture using an established experimental protocol for testing reliability. Eight healthy adult participants performed three sessions of five over-ground walking trials in their own self-selected clothing, separated by an average of 8.5 days, while eight synchronized and calibrated cameras recorded video. Three-dimensional pose estimates from the video data were used to compute lower limb joint angles. Inter-session variability, inter-trial variability, and the variability ratio were used to assess the reliability of the gait kinematics. Compared to repeatability studies based on marker-based motion capture, inter-trial variability was slightly greater than previously reported for some angles, with an average across all joint angles of 2.5°. Inter-session variability was smaller on average than all previously reported values, with an average across all joint angles of 2.8°. Variability ratios were all smaller than those previously reported with an average of 1.1, indicating that the multi-session protocol increased the total variability of joint angles by 10% of the inter-trial variability. These results indicate that gait kinematics can be reliably measured using markerless motion capture.
基于标记的运动捕捉系统固有的局限性一直阻碍着步态分析的临床应用，该系统长期以来一直是采集步态数据（包括运动学）的标准方法。无标记运动捕捉为采集步态运动学提供了一种替代方法，与基于标记的系统相比，它具有几个实际优势。本研究旨在使用既定的可靠性测试实验方案，确定基于视频的无标记运动捕捉下肢步态运动学的可靠性。八名健康成年人在穿着自选服装的情况下，平均相隔 8.5 天进行了三次五次地面行走试验，每次试验都有八台同步且校准的摄像机记录视频。从视频数据中计算出三维姿势估计，以计算下肢关节角度。通过会话间变异性、试验间变异性和变异性比来评估步态运动学的可靠性。与基于标记的运动捕捉的重复性研究相比，一些角度的试验间变异性略高于之前的报告值，所有关节角度的平均值为 2.5°。会话间变异性的平均值均小于之前所有报告的值，所有关节角度的平均值为 2.8°。变异性比均小于之前报告的值，平均值为 1.1，表明多会话方案使关节角度的总变异性增加了 10%的试验间变异性。这些结果表明，步态运动学可以使用无标记运动捕捉可靠地测量。
