Research and development of 3D printing orthotic insoles and preliminary treatment of leg length discrepancy patients

Abstract

BACKGROUND: Leg length discrepancy (LLD) can cause abnormal posture, muscle and/or joint pains, which leads to walking difficulties. The common treatment is to use a shoe lift on the shorter leg side, but this has unsatisfying results. OBJECTIVE: Through research and development, we created 3D printing orthotic insoles for LLD patients and aimed to improve their symptoms. METHODS: 1. Research and development of 3D printing orthotic insole: (1) foot scan and data acquisition; (2) insole software modeling; (3) 3D printing insole using TPU materials, and (4) post-processing. 2. Clinical observation: we customized insoles for LLD patients and required them to wear them while walking. We conducted general inquiries and a functional evaluation before and after 12 weeks of wearing insoles. RESULTS: There are seven complete cases. The joint and lower back pains were alleviated. The stride frequency, stride and pace were improved in all seven cases. Patients' overall health condition improved significantly. CONCLUSIONS: The 3D printing orthotic insoles are made with clear procedures and practical operability. By wearing insoles, patients' muscle and/or joint pains were relieved and their gaits were improved.