Customization of 3D-Printed Hinged Ankle-Foot Orthosis Based on Kinematic Evaluation from Motion Capture

Commercial hinged foot-ankle orthoses (HAFO) generally do not ensure the alignment between the mechanical and the anatomical joints, causing discomfort and unnatural walking. This paper presents a method to design a customized HAFO modeled on geometrical and kinematic data collected from a healthy 24-year-old woman. The geometry of the shank and foot was acquired through a 3D scanner. The physiological articular rotation axis (AoR) was estimated through helical axis and SARA algorithms. The identified AoR was then used to properly design the orthosis by making particular attention to the hinge position. Finally, the prototype was manufactured with fused deposition modeling technique, and its functionality was validated through gait analysis trials.