In the present study, a 3-dimensional finite element analysis (FEA) of the insole shoe orthotic was developed for analysing foot deformities. The solid model of abnormal human foot was composed of the plantar fascia which was encapsulated by soft tissue (indenture feet) against to the rubber EVA insoles. The models were explored into 3D solid using STL file of scan-foot Handy SCAN 700TM. Data of abnormal foot contour was obtained through the scanning process.
Subsequently, 3D solid model of the orthotic shoe insole was generated using the Power SHAPE CAD 2015. The finite element (FE) method of 3D meshes was run on the imported solid model using the software ABAQUS 6:13. Contact interaction between the indenter feet and the orthotic insole shoe was investigated as a function of the various sizes of shoe insole. Strategy of curve-based surface modelling (CBSmodelling) was adopted to obtain surface and solid models of the orthotic shoe insole.
The sizeof the gap between the soles of the feet to the width of the designed insole was obtained.
The simulation results show that the FEA of the solid model provides the variation of von Misses stress on each insole with a predetermined gap width. In the 3D solid model, the optimum shoe orthotic insole peak has maximum von Misses stress of 1.19x10-3 MPa which exists on the heel bone with the gap width of 1.75 mm