Structural Optimization and Finite Element Evaluation of a 3D-Printed Transtibial Prosthetic Leg for Enhanced Lightweight Performance

Lower limb amputation requires prosthetic components that are lightweight yet mechanical-ly reliable under repetitive gait loading. This study addresses this need through additive manufacturing and finite element–based structural optimization of a 3D-printed transtibial prosthetic shank. A parametric model was developed to simulate representative walking loads while varying wall thickness and circular cut-out geometry for three polymer materi-als: Acrylonitrile Butadiene Styrene (ABS), Polyethylene Terephthalate (PET), and Nylon. Results showed that a PET structure with a 15 mm wall thickness and 15 mm diameter circu-lar cut-outs provides the best compromise between structural integrity and weight reduction. This configuration reduced material volume by approximately 30% while maintaining maxi-mum deformation below 2.1 mm and a safety factor above 2. In addition, the selected design was subjected to direction-dependent loading and impact verification, confirming a stable response under gait-angle variation and occasional high-impact events. Although the study is based on simplified loading assumptions and requires experimental validation, it demon-strates a mechanically consistent framework for lightweight design of additively manufac-tured prosthetic shank components.