The Effect of 3D-Printed Custom Insoles on Plantar Pressure for Obese Individual

Abstract

ABSTRACT Introduction There are many types of insoles made for obese individuals. However, there is a need for studies on insoles produced with 3D printers using flexible materials and comparing and examining the effect of these on plantar pressure. Materials and Methods An obese individual with a body mass index (BMI) > 35 recommended by physicians to use insoles was included in this study. The individual’s foot was scanned using a 3D scanner, and insoles were designed using CAD software. The insoles were produced with TPU-75A flexible filament on a 3D printer at different fill rates (5%, 10%, and 15%). The effects of the insoles on underfoot pressures were clinically compared. Results Custom insoles with different filling ratios were made for an obese individual using flexible filament in 3D printers. The most appropriate insole print filling ratio for minimum foot pain experienced by the obese patient during their daily activities has been determined. The results reveal that 3D-printed insoles distribute the plantar pressure more effectively with significantly reduced pressure in certain foot locations (i.e., heel, under the first metatarsal) as compared with the existing insoles. Conclusions Manufactured by additive manufacturing, these insoles are produced using a fully digitized scanning process that creates virtually no material wastage. The thermoplastic polyurethane was preferred due to its favorable properties. By changing the pressure structure and internal filling system, it allows producing personalized insoles in the desired contact areas of hard and soft. Clinical Relevance This study provides evidence that insoles produced in 3D printers with flexible materials are as effective as insoles produced with traditional methods in reducing plantar pressure. Therefore, it is an alternative to traditional methods due to less labor.