Finite Element Approach Towards Selection of Appropriate Materials to Redistribute Peak Plantar Pressure in Diabetic Foot with Neuropathy

<p dir="ltr"><b>Objective: </b>The aim of this study was to assess the effect of customized insole (CMI) variations on plantar pressure in diabetic foot with neuropathy, using finite element analysis (FEA).</p><p dir="ltr"><b>Material and Methods: </b>A three-dimensional foot model was constructed using FEA to study the peak contact pressure between the foot and the CMI. Nora® Lunalastike, Ethylene Vinyl Acetate (EVA), Amfit® and TPU were chosen for insole materials; and from these eight CMI models were created. The top surface of the tibia and fibula were fixed, and a displacement of 3 mm was exerted from the ground along with upwards Achilles tendon force.</p><p dir="ltr"><b>Results:</b> The peak contact pressure contour showed that a softer material, CMI-A (E = 1.04 MPa), resulted in a better reduction of peak contact pressure compared to a stiffer material; CMI-D (E = 11 MPa). In addition, it was shown that the use of a single material to fabricate the CMI resulted in higher peak contact pressure; with the exception of CMI-A, in comparison to a dual-layer material of CMI-E and CMI-F. Using FEA, can effectively enhance the insole material selection process, without need of a trial and error practice in a clinical setting.</p><p dir="ltr"><b>Conclusion:</b> The use of dual materials to fabricate CMIs, with the softer material as a top layer, is beneficial compared to a stiffer top layer material in the reduction of peak plantar pressure for diabetic foot with neuropathy.</p>