A Three-Dimensional Printed Foot Orthosis for Flexible Flatfoot: An Exploratory Biomechanical Study on Arch Support Reinforcement and Undercut

The advancement of 3D printing and scanning technology enables the digitalization customization foot orthosis with better accuracy. However, customized insoles require rectification to direct control and/or correct deformity, particularly flatfoot. In this exploratory study, we aimed at two design features (arch stiffness arch height) using three sets 3D-printed support (R+U+, R+U?, R?U+). could be or without reinforcement (R+/?) height may not have an additional elevation, undercutting (U+/?), which were compared (no insole). Ten collegiate participants (four males six females) flexible flatfoot recruited for gait analysis on kinematics, vertical ground reaction force, plantar pressure parameters. A randomized crossover trial was conducted four conditions analyzed Friedman test pairwise Wilcoxon signed-rank test. Compared control, there significant increases in peak ankle dorsiflexion medial midfoot region, accompanied by a reduction hindfoot region insole conditions. addition, tended eversion forefoot abduction though effects significant. An stronger (R+U+) did necessarily produce more favorable outcomes, probably due over-cutting impingement. outcome study provides data assist process. Future studies should consider larger sample size stratified covariating flexibility while incorporating features, postings.