Comparison of ground reaction force of flatfoot orthoses using 3D gait analysis technology in individuals with flexible flatfoot: A cross-sectional study

BACKGROUND Various foot orthoses are used to manage flat feet deformity. Nevertheless, few studies have examined the effects of customized three-dimensional (3D) printed insole orthoses for flexible flat feet on peak ground reaction force (GRF) during gait. OBJECTIVE This study aimed to evaluate the impact of customized 3D-printed insole orthoses on peak 3D GRF parameters in individuals with flat feet during walking. METHODS Kinetic GRF data were collected during gait in twenty-four participants under general shoe insole, prefabricated insole orthosis, and customized 3D-printed insole orthosis conditions. The 3D-printed insole orthoses were manufactured based on a 3D scanner and 3D printer devices. Two force platforms were utilized to assess 3D kinetic GRF data. RESULTS Compared with the general shoe insole and prefabricated insole orthosis, participants exhibited significantly higher late anteroposterior peak GRF and late vertical peak GRF when using the 3D-printed insole orthosis condition (p < 0.05). CONCLUSION Use of 3D-printed insoles positively influenced peak late anterior and late vertical GRF during the terminal stance phase of gait. Fabrication of customized foot orthoses with 3D printing technology may address limitations associated with conventional orthoses.