Comparative Analysis of Material Characteristics and Biomechanical Performance in Passive Ankle-Foot Orthoses

Passive ankle-foot orthoses (AFOs) provide essential joint stabilization and limit excessive movement, serving as a cornerstone in biomechanical gait analysis. This study innovatively developed three distinct passive AFOs using thermoplastic polyurethane (TPU), high-impact polystyrene (HIPS), and polylactic acid (PLA) materials, along with a silicone sole, demonstrating enhanced mechanical properties and functional performance. The materials were analyzed using Field Emission Scanning Electron Microscopy (FE-SEM), tensile testing, finite element analysis (FEA), and gait analysis. In particular, FE-SEM revealed micrometer-scale surface roughness (