Peeters Koen, Natsakis Tassos, Burg Josefien, Spaepen Pieter, Jonkers Ilse, Dereymaeker Greta, Vander Sloten Jos
Biomechanics Section, Mechanical Engineering Department, Faculty of Engineering KU Leuven, Belgium.
Proc Inst Mech Eng H. 2013 Sep;227(9):955-67. doi: 10.1177/0954411913490455. Epub 2013 Jun 4.
Despite their well-known limitations, in vitro experiments have several benefits over in vivo techniques when exploring foot biomechanics under conditions characteristic of gait. In this study, we present a new setup for dynamic in vitro gait simulation that integrates a numerical model for generating the tibial kinematics control input, and we present an innovative methodology to measure full three-dimensional joint kinematics during gait simulations. The gait simulator applies forces to the tendons. Tibial kinematics in the sagittal plane is controlled using a numerical model that takes into account foot morphology. The methodology is validated by comparing joint rotations measured during gait simulation with those measured in vivo. In addition, reliability and accuracy of the control system as well as simulation input and output repeatability are quantified. The results reflect good control performance and repeatability of the control inputs, vertical ground reaction force, center of pressure displacement, and joint rotations and translations. In addition, there is a good correspondence to in vivo kinematics for most patterns of motion at the ankle, subtalar, and Chopart's joints. Therefore, these results show the relevance and validity of including specimen-specific information for defining the control inputs.
尽管存在众所周知的局限性，但在模拟步态特征条件下探索足部生物力学时，体外实验相较于体内技术仍有若干优势。在本研究中，我们展示了一种用于动态体外步态模拟的新装置，该装置集成了一个用于生成胫骨运动学控制输入的数值模型，并且我们还展示了一种在步态模拟过程中测量完整三维关节运动学的创新方法。步态模拟器向肌腱施加力。矢状面内的胫骨运动学通过一个考虑足部形态的数值模型进行控制。通过将步态模拟过程中测量的关节旋转与体内测量的关节旋转进行比较，对该方法进行了验证。此外，还对控制系统的可靠性和准确性以及模拟输入和输出的可重复性进行了量化。结果反映出控制输入、垂直地面反作用力、压力中心位移以及关节旋转和平移具有良好的控制性能和可重复性。此外，对于踝关节、距下关节和跗中关节的大多数运动模式，与体内运动学有良好的对应关系。因此，这些结果表明了纳入特定标本信息以定义控制输入的相关性和有效性。
