Borucka Aleksandra, Ciszkiewicz Adam
Institute of Applied Mechanics, Cracow University of Technology, 31-155 Cracow, Poland.
Materials (Basel). 2019 Aug 17;12(16):2621. doi: 10.3390/ma12162621.
The ankle is one of the most complicated joints in the human body. Its features a plethora of elements with complex behavior. Their functions could be better understood using a planar model of the joint with low parameter count and low numerical complexity. In this study, an accurate planar model of the ankle with optimized material parameters was presented. In order to obtain the model, we proposed an optimizational approach, which fine-tuned the material parameters of two-dimensional links substituting three-dimensional ligaments of the ankle. Furthermore, the cartilage in the model was replaced with Hertzian contact pairs. The model was solved in statics under moment loads up to 5 Nm. The obtained results showed that the structure exhibited angular displacements in the range of the ankle joint and that their range was higher in dorsiflexion than plantarflexion. The structure also displayed a characteristic ramp up of the angular stiffness. The results obtained from the optimized model were in accordance with the experimental results for the ankle. Therefore, the proposed method for fine-tuning the material parameters of its links could be considered viable.
踝关节是人体最复杂的关节之一。它具有大量行为复杂的组成部分。使用参数数量少且数值复杂度低的关节平面模型，可以更好地理解它们的功能。在本研究中，提出了一种具有优化材料参数的精确踝关节平面模型。为了获得该模型，我们提出了一种优化方法，该方法对替代踝关节三维韧带的二维连杆的材料参数进行了微调。此外，模型中的软骨被赫兹接触对所取代。该模型在高达5 Nm的力矩载荷下进行静力学求解。所得结果表明，该结构在踝关节的角度位移范围内表现出角位移，且背屈时的位移范围高于跖屈时。该结构还显示出角刚度的特征性上升。优化模型得到的结果与踝关节的实验结果一致。因此，所提出的微调其连杆材料参数的方法可被认为是可行的。
