Lavaill Maxence, Martelli Saulo, Kerr Graham K, Pivonka Peter
School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia.
Queensland Unit for Advanced Shoulder Research, Brisbane, QLD 4000, Australia.
Life (Basel). 2022 May 31;12(6):819. doi: 10.3390/life12060819.
The assessment of shoulder kinematics and kinetics are commonly undertaken biomechanically and clinically by using rigid-body models and experimental skin-marker trajectories. However, the accuracy of these trajectories is plagued by inherent skin-based marker errors due to marker misplacements (offset) and soft-tissue artifacts (STA). This paper aimed to assess the individual contribution of each of these errors to kinematic and kinetic shoulder outcomes computed using a shoulder rigid-body model. Baseline experimental data of three shoulder planar motions in a young healthy adult were collected. The baseline marker trajectories were then perturbed by simulating typically observed population-based offset and/or STA using a probabilistic Monte-Carlo approach. The perturbed trajectories were then used together with a shoulder rigid-body model to compute shoulder angles and moments and study their accuracy and variability against baseline. Each type of error was studied individually, as well as in combination. On average, shoulder kinematics varied by 3%, 6% and 7% due to offset, STA or combined errors, respectively. Shoulder kinetics varied by 11%, 27% and 28% due to offset, STA or combined errors, respectively. In conclusion, to reduce shoulder kinematic and kinetic errors, one should prioritise reducing STA as they have the largest error contribution compared to marker misplacements.
肩部运动学和动力学的评估通常通过使用刚体模型和实验性皮肤标记轨迹在生物力学和临床方面进行。然而，由于标记放置不当（偏移）和软组织伪影（STA），这些轨迹的准确性受到基于皮肤的固有标记误差的困扰。本文旨在评估这些误差中的每一个对使用肩部刚体模型计算的肩部运动学和动力学结果的个体贡献。收集了一名年轻健康成年人肩部三个平面运动的基线实验数据。然后，使用概率蒙特卡洛方法模拟典型观察到的基于人群的偏移和/或STA，对基线标记轨迹进行扰动。然后将扰动后的轨迹与肩部刚体模型一起用于计算肩部角度和力矩，并研究它们相对于基线的准确性和变异性。分别对每种类型的误差进行了单独研究，以及组合研究。平均而言，由于偏移、STA或组合误差，肩部运动学分别变化了3%、6%和7%。由于偏移、STA或组合误差，肩部动力学分别变化了11%、27%和28%。总之，为了减少肩部运动学和动力学误差，应优先减少STA，因为与标记放置不当相比，它们的误差贡献最大。
