Laboratory for Biomechanics and Biomaterials, Department of Orthopaedic Surgery, Hannover Medical School, Anna-von-Borries-Str. 1-7, 30625, Hannover, Germany.
Leibniz Universität Hannover, Institute of Mechatronic Systems, An der Universität 1, 30823, Garbsen, Germany.
Sci Rep. 2024 Sep 5;14(1):20666. doi: 10.1038/s41598-024-71409-z.
The use of marker-based optical motion capture to estimate joint kinematics during gait is currently limited by errors associated with soft-tissue-induced motion artefacts (STIMA) and ambiguity in landmark palpation. This study therefore presents a novel protocol aiming to Minimize Knee Soft-Tissue Artefacts (MiKneeSoTA) and their effect on kinematic estimates. Relying on an augmented marker set and a new inverse kinematics approach, our method leverages frame-by-frame optimization to adjust best-fit cylinders that have been automatically generated based on the relative position of lower limb markers during an initial static trial. Tibiofemoral rotations and translations are then calculated along the anatomical joint axes based on the relative 3D motion of these cylinders. When compared against the conventional Helen-Hayes approach, in vivo assessment of fifteen healthy subjects revealed the MiKneeSoTA approach led to kinematic profiles with significantly lower standard deviations in joint rotations across trials, and even visibly reduced the presence of high frequency fluctuations presumably associated with e.g. soft-tissue vibration. In addition to agreeing with previously published bone pin and fluoroscopy datasets, our results illustrate MiKneeSoTA's ability to abate the effect of STIMA induced by lateral knee ligaments. Our findings indicate that MiKneeSoTA is in fact a promising approach to mitigate knee joint STIMA and thus enable the previously unattainable accurate estimation of translational knee joint motion with an optoelectronic system.
基于标记的光学运动捕捉技术在步态分析中用于估计关节运动学，但目前受到软组织运动伪影（STIMA）相关误差以及标志点触诊的模糊性限制。因此，本研究提出了一种新的方案，旨在最大限度地减少膝关节软组织伪影（MiKneeSoTA）及其对运动学估计的影响。该方法依赖于增强的标记集和新的逆向运动学方法，通过逐帧优化来调整最佳拟合圆柱体，这些圆柱体是基于下肢标记在初始静态试验中的相对位置自动生成的。然后，根据这些圆柱体的相对 3D 运动，沿着解剖关节轴计算胫股旋转和平移。与传统的 Helen-Hayes 方法相比，对 15 名健康受试者的体内评估表明，MiKneeSoTA 方法导致关节旋转的运动学曲线在试验间的标准偏差显著降低，甚至明显减少了与例如软组织振动相关的高频波动的存在。除了与先前公布的骨钉和荧光透视数据集一致外，我们的结果还表明 MiKneeSoTA 能够减轻膝关节外侧韧带引起的 STIMA 效应。我们的研究结果表明，MiKneeSoTA 实际上是一种有前途的方法，可以减轻膝关节 STIMA，从而实现以前无法实现的使用光电系统对膝关节平移运动进行准确估计。
