School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD, Australia.
Queensland Unit for Advanced Shoulder Research, Brisbane, QLD, Australia.
Biomech Model Mechanobiol. 2022 Oct;21(5):1561-1572. doi: 10.1007/s10237-022-01606-0. Epub 2022 Jul 22.
Joint motion calculated using multi-body models and inverse kinematics presents many advantages over direct marker-based calculations. However, the sensitivity of the computed kinematics is known to be partly caused by the model and could also be influenced by the participants' anthropometry and sex. This study aimed to compare kinematics computed from an anatomical shoulder model based on medical images against a scaled-generic model and quantify the effects of anatomical errors and participants' anthropometry on the calculated joint angles. Twelve participants have had planar shoulder movements experimentally captured in a motion lab, and their shoulder anatomy imaged using an MRI scanner. A shoulder multi-body dynamics model was developed for each participant, using both an image-based approach and a scaled-generic approach. Inverse kinematics have been performed using the two different modelling procedures and the three different experimental motions. Results have been compared using Bland-Altman analysis of agreement and further analysed using multi-linear regressions. Kinematics computed via an anatomical and a scaled-generic shoulder models differed in average from 3.2 to 5.4 degrees depending on the task. The MRI-based model presented smaller limits of agreement to direct kinematics than the scaled-generic model. Finally, the regression model predictors, including anatomical errors, sex, and BMI of the participant, explained from 41 to 80% of the kinematic variability between model types with respect to the task. This study highlighted the consequences of modelling precision, quantified the effects of anatomical errors on the shoulder kinematics, and showed that participants' anthropometry and sex could indirectly affect kinematic outcomes.
使用多体模型和运动学逆解计算关节运动比基于直接标记的计算具有许多优势。然而，计算运动学的灵敏度已知部分是由模型引起的，也可能受到参与者的人体测量和性别的影响。本研究旨在比较基于医学图像的解剖肩部模型与缩放通用模型计算的运动学，并量化解剖学误差和参与者人体测量对计算关节角度的影响。12 名参与者在运动实验室中进行了平面肩部运动的实验捕获，并使用 MRI 扫描仪对其肩部解剖结构进行了成像。为每位参与者开发了一种肩部多体动力学模型，分别使用基于图像的方法和缩放通用方法。使用两种不同的建模过程和三种不同的实验运动进行了运动学逆解。使用一致性的 Bland-Altman 分析比较了结果，并使用多元线性回归进行了进一步分析。根据任务的不同，通过解剖学和缩放通用肩部模型计算的运动学平均相差 3.2 到 5.4 度。基于 MRI 的模型与缩放通用模型相比，直接运动学的一致性限制更小。最后，回归模型预测因子，包括参与者的解剖学误差、性别和 BMI，解释了模型类型相对于任务的运动学变异性的 41%至 80%。本研究强调了建模精度的后果，量化了解剖学误差对肩部运动学的影响，并表明参与者的人体测量和性别可能会间接影响运动学结果。
