IEEE Trans Biomed Eng. 2018 Apr;65(4):715-722. doi: 10.1109/TBME.2017.2716186. Epub 2017 Jun 15.
Little information is available in the existing literature regarding the influence of the scapular kinematic estimate method on musculoskeletal analysis. This study aimed to assess the propagation of errors due to the method used for scapular kinematics reconstruction in the workflow of musculoskeletal modeling (joint kinematics, joint torques, muscle force, and joint reaction force) in shoulder and upper-limb movements.
Two participants performed functional (arm elevation and rotation), daily life (eating and reaching pants pockets), and sports movements (a simulated throwing maneuver). Shoulder kinematics were obtained with five multibody kinematics methods: intracortical pins (Pins, reference method), International Society of Biomechanics (ISB), Jackson (Jack), Projection (Proj), and Ellipsoid (Ell) methods. For the five kinematics methods, joint torques, muscle forces, and glenohumeral joint reaction forces were computed with the Delft Shoulder and Elbow musculoskeletal model.
Differences up to 30° in glenohumeral joint kinematics, compared to the Pins method, resulted in differences less than 3 N.m in joint torque estimation. However, these also resulted in differences up to 50 and 831 N in the muscle force and joint reaction force estimate, respectively, in comparison to the reference method (Pins). No method yielded the worst or best results in comparison to the Pins method but the differences were task-specific.
We concluded that shoulder biomechanical studies based on skin markers should be completed with caution when assessing joint angles, muscle forces, and glenohumeral joint reaction forces, while researchers may be more confident with the evaluation of shoulder joint torques.
现有文献中关于肩胛骨运动学估计方法对肌肉骨骼分析影响的信息很少。本研究旨在评估在肌肉骨骼建模（关节运动学、关节扭矩、肌肉力和关节反作用力）工作流程中，由于肩胛骨运动学重建方法而导致的误差传播，在肩部和上肢运动中。
两名参与者进行了功能（手臂抬高和旋转）、日常生活（吃饭和伸手到裤子口袋）和运动（模拟投掷动作）运动。使用五种多体运动学方法（皮质内钉（Pins，参考方法）、国际生物力学学会（ISB）、Jackson（Jack）、Projection（Proj）和Ellipsoid（Ell）方法）获得肩部运动学。对于五种运动学方法，使用 Delft 肩部和肘部肌肉骨骼模型计算关节扭矩、肌肉力和盂肱关节反作用力。
与 Pins 方法相比，肩胛骨关节运动学的差异高达 30°，导致关节扭矩估计的差异小于 3 N.m。然而，与参考方法（Pins）相比，这些方法还导致肌肉力和关节反作用力的估计分别相差高达 50 和 831 N。与 Pins 方法相比，没有一种方法的结果最差或最好，但差异是特定于任务的。
我们得出结论，当评估关节角度、肌肉力和盂肱关节反作用力时，基于皮肤标记的肩部生物力学研究应谨慎完成，而研究人员可能对评估肩关节扭矩更有信心。
