Modular Lower Limb 3D-Printed Orthoprosthesis for Toddlers With Fibular Hemimelia

Toddlers with congenital limb deficiencies, such as fibular hemimelia, face major barriers to independent mobility during a critical windowof motor development. Despite the need for early intervention, existing orthoprosthetic solutions are often inaccessible and poorly suited to the anatomical and functional needs of children aged 12–36 months. This study presents a novel, user-centered approach to a modular pediatric lower limb orthoprosthesis dubbed +Limb developed in close collaboration with caregivers, physicians, and therapists. Using additive manufacturing, successive prototypes were rapidly produced and tested in a clinical setting. The final device met key requirements for modularity, light weight, postural support, and adjustability. Functional evaluations demonstrated significant improvements, including correction of a 4.5 cm leg length discrepancy, reduction of pelvic tilt from 15° to 0°, and initiation of unassisted gait with controlled knee flexion up to 45°. To study how the body and muscles responded, different sensors were used, including pressure sensors (FSRs), muscle activity sensors (EMG), and a pressure plate for foot contact analysis. This case study demonstrates the feasibility of a low-cost, customizable orthoprosthesis for toddlers with fibular hemimelia and emphasizes the advantages of combining additive manufacturing and sensor-based feedback to support early-stage rehabilitation in pediatric populations.