3D-printed prosthetic foot design: Mechanical similarity and testing

This study introduces a novel, accessible approach for designing a lower-limb prosthetic foot intended for production on standard 3D printers, thereby making it available to any individual with the requisite resources. A cost-effective prototyping process was employed to minimize material waste and optimize testing through the application of dimensional analysis and scaling methodologies. The methodology was validated for predicting full-scale performance accurately through the testing of smaller-scale prototypes to failure, which preserved the force-to-displacement ratio across scales and achieved a relative error of 3.6%. The prosthesis was found to meet the mechanical requirements of UNE-EN ISO 10328:2016 through static strength testing. The scaled methodology allows for the creation of reliable prostheses at a reduced cost, thereby increasing the accessibility of advanced prosthetic solutions. This research not only corroborates the viability of 3D-printed prostheses for clinical use but also establishes a framework for future designs, offering significant potential for low-cost, scalable solutions in prosthetic engineering. • The study designed a 3D-printed prosthetic foot, cutting costs and waste through precise dimensional analysis and scaling. • Made of PLA, the prosthesis passed UNE-EN ISO 10328:2016 tests, ensuring mechanical strength and clinical feasibility. • Reliability was validated by correlating scaled prototypes with full-size models, laying the groundwork for future improvements. • Results highlight scaling and dimensional analysis as key to accessible prosthetics, driving innovation and new technologies.