Investigation of the interaction phenomena between foot and insole by means of a numerical approach

Abstract

The biomechanical response of foot with regard to interaction phenomena occurring at interface with insole inserted in\ud the shoe is investigated by using a numerical approach. At this purpose, a complex three-dimensional model of the foot\ud is defined from biomedical images, while insole conformation is acquired by laser scanner technique, leading to the finite\ud element discretization. Foot tissues are characterized by means of specific constitutive visco-hyperelastic anisotropic formulations,\ud recalling previous research activity. The mechanical behavior of insole material is analyzed by means of experimental\ud compression tests that highlight the geometric and material non-linear response, represented by a hyperelastic\ud formulation, while a hyperfoam formulation is assumed for the sole. Numerical analysis considers the mid-stance phase\ud of the gait and allows to interpret the response of overall foot, insole and sole system. The investigation represents a\ud preliminary step of a parametric analysis addressed to support footwear design considering different configurations of\ud components. As matter of example, the influence of variation in insole material properties is reported

Gait-Specific Optimization of Composite Footwear Midsole Systems, Facilitated through Dynamic Finite Element Modelling

“…The inclusion of a foot model will also be considered in the future. Despite the fact that the implementation of such foot-shoe interactions [35, 36] arrives at similar conclusions as shown here, considering tissue properties, would provide refined insight to tissue-specific loading. This could be vital for patients in need of prescribed therapeutic footwear, i.e., patients suffering from diabetes and peripheral neuropathy [37], as ground reaction forces have been associated with lower extremity skin breakdown.…”

Investigation of the mechanical behaviour of the plantar soft tissue during gait cycle: Experimental and numerical activities

“…Therefore, the numerical model had to account for an averaged configuration of the human foot. The model of the foot was developed based on magnetic resonance imaging (MRI) and computed tomography (CT) data, 3 from a human subject without pathology and assuming an unloaded position. An imaging density segmentation software, which applies the density segmentation techniques on the Digital Imaging and Communications in Medicine (DICOM) images, obtained 3D computer-aided design (CAD) solid models.…”

“…A relative motion between the foot and the plane was imposed along the Y-direction. 1,3 The friction between the skin and the rubber layer was modelled using contact surfaces with a friction coefficient of 0.61 as reported in the literature. [27][28][29] Once the first step was completed, the second step of the analysis was developed to interpret the phase between the heel strike and the midstance.…”

“…The experimental tests and numerical analyses can be integrated to obtain accurate and reliable information on foot mechanics. [1][2][3][4] Experimental techniques evaluate mechanical loads and kinematics of the foot as the ground reaction forces and angle configuration during gait cycle. Numerical approaches are used to evaluate the loading effects within the biological structure as stress and strain distributions.…”

“…Finite element modelling has the capability to calculate the data characterizing internal stress states and their evolution within bony structures under different static and dynamic loading scenarios. [1][2][3][4] Moreover, numerical models allow evaluating the mechanical responses of the foot in healthy or pathological conditions, considering different mechanical responses of foot tissues. Two-dimensional and three-dimensional (3D) finite element models of the foot have been proposed over the years, to better understand the stress distribution during the gait cycle and to improve orthotics and footwear design.…”