Evaluation of Personalised 3D Printed Functionally Graded Metamaterial Foot Orthoses With an Offloading Boot

This study explored the potential of 3D printing and functionally graded metamaterials (FGMs) to enhance the mechanical function of personalised foot orthoses, particularly for offloading in diabetes-related foot ulceration (DFU) treatment. FGMs allow stiffness to vary across an orthosis, enabling softer support under high-pressure areas and firmer support elsewhere. A novel automated workflow was developed to design and 3D print FGM orthoses based on plantar pressure data, and three stiffness-distribution algorithms were compared against traditional contoured EVA orthoses and flat prefabricated devices.

Results showed that contoured 3D printed FGM orthoses achieved similar forefoot load reduction to contoured EVA orthoses when used in an offloading boot, with performance influenced by the stiffness algorithm used. These findings highlight the potential for rapid, low-cost, point-of-care manufacturing of effective offloading orthoses and provide early guidance on stiffness tuning for plantar pressure redistribution. Future research will test these designs in people with peripheral neuropathy and DFU.