Benefits of 3D Printed and Customized Anatomical Footwear Insoles for Plantar Pressure Distribution

During walking, the foot is in direct contact with the insole of the footwear, and it affects the biomechanics of the whole human body. The aim of this study was to compare the plantar pressure distribution while walking in the same footwear in three different situations: with an original footwear insole, with an ethylene-vinyl acetate customized insole, and with a 3D printed anatomical insole to find out the optimal insoles for people with a normal, flat, and high arched foot according to the plantar pressure relief. Fifty-one adults were grouped into three groups (normal foot, flat foot, and high arched foot geometry). The feet of the randomly selected subjects from each group were scanned, and the insoles were designed on the basis of the foot model. These models were then used for the 3D printing. The plantar pressure distribution was observed when walking in all three different insole types for each of the three subjects with the different foot types. The peak pressure values in the forefoot, midfoot, and rearfoot and contact area were compared. The results of the study show that customized insoles influence the plantar pressure distribution mainly in people with a flat foot or with a high arched foot deformity. This influence is dependent on the type of the customized insoles, mainly in people with a high arched foot. People with a flat foot deformity have a similar plantar pressure relief in the thermoplastic insoles as those in the 3D printed insoles, and both these customized insoles can be used as a supplementary therapeutic instrument. Our study showed that the biggest attention, with regards to customizing insoles, is required by people with a high arched foot deformity, and we recommend that these people use fully customized insoles which can be guaranteed with 3D printing techniques.