Univ Lyon, Université Claude Bernard Lyon 1, Laboratoire Interuniversitaire de Biologie de la Motricité, UR 7424, F-69622 Villeurbanne, France; TRINOMA, Villefort, France.
Univ Lyon, Université Claude Bernard Lyon 1, Laboratoire Interuniversitaire de Biologie de la Motricité, UR 7424, F-69622 Villeurbanne, France.
J Biomech. 2023 Oct;159:111795. doi: 10.1016/j.jbiomech.2023.111795. Epub 2023 Sep 9.
Scapular kinematic estimates are altered by soft tissue artefacts, therefore experimental and numerical methods should be developed to improve their accuracy. This study aimed to assess the influence of weights applied to the scapula markers within a closed-loop multibody kinematic optimization on scapular kinematic estimates. Fifteen healthy volunteers performed static postures mimicking analytical, daily living and sport movements. Scapulo-thoracic angles were computed either from a scapula locator as the reference, or from a closed-loop multibody-kinematic optimization (MKO) including a participant-specific point-on-ellipsoid scapulothoracic joint. Weights applied to scapula markers in the MKO were optimized to minimize the difference in scapular orientation from the reference. Optimizing weighting sets significantly (p < 0.0001) improved scapular orientation from 0.9° to 12.1° in comparison to scapular kinematics estimated with non-optimized weighting sets. The mean optimized weighting set contained no neglectable weight for all markers from the acromion to the medial border of the scapular spine but showed no significant difference (p = 0.547) compared to homogeneous weights. Optimized weighting sets were participant- and movement- specific. To conclude, homogenous weights applied on redundant markers located from acromion to scapular medial border spine are recommended when estimating scapular kinematics in upper limb MKO.
肩胛骨运动学估计会受到软组织伪影的影响，因此应该开发实验和数值方法来提高其准确性。本研究旨在评估在闭环多体运动学优化中对肩胛骨标记施加重量对肩胛骨运动学估计的影响。15 名健康志愿者进行了模拟分析、日常活动和运动的静态姿势。肩胛骨-胸角度是从肩胛骨定位器作为参考计算得出的，或者从包括参与者特定的点在椭球肩胛骨关节的闭环多体运动学优化（MKO）中计算得出的。在 MKO 中施加到肩胛骨标记的权重进行了优化，以最小化参考与肩胛骨方位之间的差异。与未优化的权重集相比，优化权重集可显著（p<0.0001）改善肩胛骨方位，从 0.9°提高到 12.1°。与均匀权重相比，优化的权重集对于从肩峰到肩胛骨脊柱内侧边界的所有标记都没有可忽略的权重，但没有显著差异（p=0.547）。优化的权重集是参与者和运动特异性的。总之，在估计上肢 MKO 中的肩胛骨运动学时，建议在从肩峰到肩胛骨脊柱内侧边界的冗余标记上施加均匀权重。
