Iterative Design and Additive Manufacturing of a Low-Cost Modular Transtibial Prosthesis: Technical Report

This technical report documents an engineering case study on the design, iterative prototyping,preliminary physical observations, and direct material cost analysis of an experimental modulartranstibial prosthesis fabricated via desktop FDM 3D printing. Rather than presenting a clini-cally validated alternative to commercial devices, this work records a low-cost, rapidly iterablearchitecture developed for an adult patient with a diabetic unilateral amputation under severefinancial constraints. The five-module design combines rigid polylactic acid (PLA) load-bearingmembers with flexible thermoplastic polyurethane (TPU 95A) interface components and me-chanical couplings. Supervised static standing and brief assisted walking trials informed threeiterative redesigns of the foot module and socket, culminating in an anatomically contouredsocket molded over a plaster positive of the residual limb. Total direct raw material cost forthe 762 g printed assembly was approximately $14–$15 USD ($21,345 ARS). Digital manufactur-ing models are shared under a Creative Commons Attribution-NonCommercial 4.0 International(CC BY-NC 4.0) license to provide an open empirical baseline for accessible assistive technologyresearch. Keywords: Transtibial prosthesis, additive manufacturing, FDM 3D printing, modular socket, diabetic amputation, low-cost assistive technology, open-source hardware.