The existing plantar pressure collection system can not provide accurate and quantitative data for the lower extremity motor function assessment of patients wearing orthoses, and can not reflect the changes of plantar support point pressure during rehabilitation walking in pronation. In this paper, an integrated intelligent ankle-foot orthosis based on plantar pressure sensor is designed. Four thin film pressure sensors are used to collect pressure values in different areas of the plantar when patients wear the orthosis and walk, and a linear voltage conversion module is used to convert resistance signals into voltage signals. Hi3861 single chip microcomputer is used for A/D conversion and data is uploaded to the terminal through WiFi function to monitor and store data, so as to solve the problem that patients cannot provide continuous rehabilitation data during follow-up visits. In order to verify the reliability of the system, the plantar pressure data of different walks in different cycles were collected. The analysis found that after the patients wore the intelligent ankle-foot orthoses, the pressure of the first metatarsal bone in the percentage of body weight increased, the pressure of the fifth metatarsal bone decreased, and the plantar load distribution tended to be normal. The designed device could also be used for human gait analysis of the patients with pronation.
According to the orthopedic principle based on the three-point force system, this study aimed to reveal the orthopedic effect and patterns of the orthopedic based on this system in 3 patients with strephenopodia through the weight-bearing stance phase experiment and numerical simulation analysis of ankle-foot orthoses (AFOs). After the correction with AFOs, Under the pressure tolerance of human skin, different three correction forces were applied to the medial heel, above the medial ankle, below the lateral ankle and the first metatarsal bone,the weight-bearing region of the affected foot gradually shifted to the normal region of the first metatarsal bone, the fifth metatarsal bone, and the heel. The weight-bearing capacity of the affected foot increased by 11.4%. After the three-point force was adjusted for the AFO, the distribution of the plantar weight-bearing region became more uniform, and the supporting force of the affected foot increased significantly, the weight-bearing capacity of the affected foot increased to 15.19%, which approached the theoretical value. When the three-point force of was over-adjusted to exceed the pain threshold, the weight-bearing capacity of the affected foot decreased by 2.79% compared with the theoretical value. It was confirmed that the foot varus angle was attenuated significantly 8 weeks after the orthopedic with three-point force system. Further, the strephenopodia with 10° was corrected with the finite element method based on the three-point force principle, and orthopedic angle and the plantar weight-bearing region before and after the correction were also obtained, The visualization of orthopedic effects and the orthotic principle is clear contributes to clinicians provide important scientific reference for the formulation of scientific and accurate orthopedic regimens.Level of Clinical Evidence 4 Retrospective Cohort Study