Department of Industrial Engineering, Centre of Mechanics of Biological Materials, University of Padova, Via G. Colombo 3, I-35131 Padova, Italy.
Med Eng Phys. 2013 Apr;35(4):441-7. doi: 10.1016/j.medengphy.2012.06.008. Epub 2012 Jul 11.
A combined experimental and numerical approach is used to investigate the interaction phenomena occurring between foot and footwear during the heel strike phase of the gait. Two force platforms are utilised to evaluate the ground reaction forces of a subject in bare and shod walking. The reaction forces obtained from the experimental tests are assumed as loading conditions for the numerical analyses using three dimensional models of the heel region and of the running shoe. The heel pad region, as fat and skin tissues, is described by visco-hyperelastic and fibre-reinforced hyperelastic formulations respectively and bone region by a linear orthotropic formulation. Different elastomeric foams are considered with regard to the outsole, the midsole and the insole layers. The mechanical properties are described by a hyperfoam formulation. The evaluation of the mechanical behaviour of the heel pad tissues at the heel strike in bare and shod conditions is performed considering different combinations of materials for midsole and insole layers. Results allow for the definition of the influence of different material characteristics on the mechanical response of the heel pad region, in particular showing the compressive stress differentiation in the bare and shod conditions.
采用实验和数值相结合的方法研究了步态中足跟冲击阶段脚和鞋之间的相互作用现象。使用两个力台评估了受试者在赤脚和穿鞋行走时的地面反作用力。将实验测试中获得的反作用力作为数值分析的加载条件，使用足跟区域和跑鞋的三维模型进行分析。足跟垫区域（如脂肪和皮肤组织）分别采用粘弹性超弹性和纤维增强超弹性公式以及线性各向异性公式来描述。考虑了不同的弹性泡沫，包括外底、中底和鞋垫层。通过超泡沫配方描述了机械性能。在赤脚和穿鞋条件下，考虑到中底和鞋垫层的不同材料组合，对足跟垫组织在足跟冲击时的力学行为进行了评估。结果可定义不同材料特性对足跟垫区域力学响应的影响，特别是显示了赤脚和穿鞋条件下的压缩应力差异。
