Naemi Roozbeh, Chockalingam Nachiappan
a Faculty of Health, Staffordshire University , Leek Road, Stoke on Trent , ST4 2DF , UK.
Comput Methods Biomech Biomed Engin. 2013;16(12):1273-7. doi: 10.1080/10255842.2012.666795. Epub 2012 Apr 11.
Midsole force-deformation pattern has important implications in determining the kinematics and kinetics of foot during locomotion. Furthermore, the midsole stiffness and viscosity determine the midsole's force-deformation behaviour. Despite the importance of stiffness and damping components of the midsole reaction, which determines the shoe-specific ground reaction forces during locomotion, there is still a lack of methodology to quantify them separately. The purpose of this study was to develop a method of extracting the shoe-specific midsole stiffness and damping components during uniaxial compression testing. For this purpose, the force-deformation behaviour of the sole was modelled as a system consisting of a nonlinear spring and a nonlinear damper. Based on the fact that the stiffness and damping component of the midsole reaction force acts in favour during loading, and work against each other during unloading, the stiffness and damping components were separated. Utilising a curve-fitting technique, a parametric curve represented by the stiffness and damping components of the midsole reaction force model was fitted to each components of force-deformation data to extract the parameters. Statistical tests indicated that the proposed method is reliable for extracting the midsole reaction model parameters with the stiffness and damping components producing favorable results (R² 0.998 ± 0.000 and 0.984 ± 0.018/root mean squared error of 5.550 ± 0.954 and 3.286 ± 2.504, respectively).
中底力-变形模式在确定步行过程中足部的运动学和动力学方面具有重要意义。此外，中底的刚度和粘性决定了中底的力-变形行为。尽管中底反应的刚度和阻尼成分很重要，它们决定了步行过程中特定鞋子的地面反作用力，但仍然缺乏将它们分别量化的方法。本研究的目的是开发一种在单轴压缩测试期间提取特定鞋子中底刚度和阻尼成分的方法。为此，将鞋底的力-变形行为建模为一个由非线性弹簧和非线性阻尼器组成的系统。基于中底反作用力的刚度和阻尼成分在加载过程中起作用且在卸载过程中相互对抗这一事实，将刚度和阻尼成分分离。利用曲线拟合技术，将由中底反作用力模型的刚度和阻尼成分表示的参数曲线拟合到力-变形数据的每个成分上以提取参数。统计测试表明，所提出的方法对于提取中底反应模型参数是可靠的，刚度和阻尼成分产生了良好的结果（R²分别为0.998±0.000和0.984±0.018/均方根误差分别为5.550±0.954和3.286±2.504）。
