Instituto de Biomecánica de Valencia, Universitat Politècnica de València, edifici 9C. Camí de Vera, s/n, 46022 València, Spain.
Instituto Universitario de Automática e Informática Industrial, Universitat Politècnica de València, edifici 1F. Camí de Vera, s/n, 46022 València, Spain.
Gait Posture. 2022 Sep;97:28-34. doi: 10.1016/j.gaitpost.2022.07.001. Epub 2022 Jul 5.
Combining the accuracy of marker-based stereophotogrammetry and the usability and comfort of markerless human movement analysis is a difficult challenge. 3D temporal scanners are a promising solution, since they provide moving meshes with thousands of vertices that can be used to analyze human movements.
Can a 3D temporal scanner be used as a markerless system for gait analysis with the same accuracy as traditional, marker-based stereophotogrammetry systems?
A comparative study was carried out using a 3D temporal scanner synchronized with a marker-based stereophotogrammetry system. Two gait cycles of twelve healthy adults were measured simultaneously, extracting the positions of key anatomical points from both systems, and using them to analyze the 3D kinematics of the pelvis, right hip and knee joints. Measurement differences of marker positions and joint angles were described by their root mean square. A t-test was performed to rule out instrumental errors, and an F-test to evaluate the amplifications of marker position errors in dynamic conditions.
The differences in 3D landmark positions were between 1.9 and 2.4 mm in the reference pose. Marker position errors were significantly increased during motion in the medial-lateral and vertical directions. The angle relative errors were between 3% and 43% of the range of motion, with the greatest difference being observed in hip axial rotation.
The differences in the results obtained between the 3D temporal scanner and the marker-based system were smaller than the usual errors due to lack of accuracy in the manual positioning of markers on anatomical landmarks and to soft-tissue artefacts. That level of accuracy is greater than other markerless systems, and proves that such technology is a good alternative to traditional, marker-based motion capture.
将基于标记的立体摄影测量术的准确性与无标记人体运动分析的易用性和舒适性相结合是一项艰巨的挑战。3D 时间扫描仪是一种很有前途的解决方案，因为它们提供了具有数千个顶点的移动网格，可用于分析人体运动。
3D 时间扫描仪能否像传统的基于标记的立体摄影测量系统一样，作为一种无标记的步态分析系统，具有相同的准确性？
使用与基于标记的立体摄影测量系统同步的 3D 时间扫描仪进行了一项比较研究。同时测量了 12 位健康成年人的两个步态周期，从两个系统中提取关键解剖点的位置，并使用这些位置分析骨盆、右髋和膝关节的 3D 运动学。通过均方根描述标记位置和关节角度的测量差异。进行 t 检验以排除仪器误差，并进行 F 检验以评估动态条件下标记位置误差的放大倍数。
参考姿势下 3D 标志点位置的差异在 1.9 到 2.4 毫米之间。在横向和垂直方向上，标记位置误差在运动过程中显著增加。相对角度误差在运动范围的 3%到 43%之间，髋关节轴向旋转的差异最大。
3D 时间扫描仪和基于标记的系统之间的结果差异小于由于手动标记在解剖标志上的定位不准确和软组织伪影引起的通常误差。这种精度水平高于其他无标记系统，证明了这项技术是传统基于标记的运动捕捉的良好替代方案。
