The effect of customised plantar pressure accommodated 3D printed insoles on footwear cushioning during walking

• Main Author: Seet, Nicholas Wenhan
• Other Authors: Leong Kah Fai
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Mechanical engineering::Prototyping; Engineering::Aeronautical engineering
• Online Access: https://hdl.handle.net/10356/149045
• Institution: Nanyang Technological University

Orthotic insoles are shoe inserts that are commonly prescribed by podiatrists to address a range of biomechanical deficiencies. This is often achieved via the inclusion of additional cushioning and support features. However, traditional methods of insole production are time consuming and costly. The use of 3D printing in the production of orthotic insoles have been explored and are currently utilised in various commercially available insoles. However, the use of 3D printing techniques have not been used for the purpose of location specific plantar pressure reduction to reduce mean peak plantar pressures and thus achieve the redistribution of plantar pressures throughout the foot. Therefore, the objective of this study was to design and produce a customised 3D printed insole which achieves plantar pressure redistribution throughout the foot, the reduction of mean peak plantar pressures, as well as the reduction of rearfoot inversion or eversion angles. Three participants were involved in this study. An initial 3D scan of the participants’ feet was conducted to obtain the 3D model of the feet, which would then be utilised in the design of the customised insoles via Computer Aided Design (CAD). Various cushioning properties were explored before settling on the use of infill patterns and densities to vary the hardness of material at specific locations of the insoles. Plantar pressure measurements and distributions were obtained, and iterations of the insoles were produced whereby the infill density of locations with high pressure readings were reduced. The final pressure accommodated insoles achieved mixed results in the reduction of rearfoot eversion angles, with several insoles increasing the rearfoot eversion angles of participants. However, these insoles achieved lower mean peak plantar pressures for two participants as compared to the default insoles, and achieved plantar pressure redistribution for all three participants. In addition, the pressure accommodated insole for one participant resulted in lower mean peak plantar pressures than that of a commercially available orthotic insole.