ARFI elastography is a reliable imaging modality for quantifying the stiffness of contracting muscles. Additionally, the characterization of pathological soft tissues by ARFI elastography would be a promising clinical practice for patients with musculoskeletal issues.

Objective To evaluate the long-term effect of a custom-made rigid foot orthosis (RFO) in children older than 6 years with pes planus (flat foot). Methods Medical records of 42 children diagnosed with flexible pes planus who were fitted with RFOs based on the inverted technique and underwent more than four consecutive radiological studies were reviewed. Resting calcaneal stance position (RCSP), anteroposterior talocalcaneal angle, lateral talocalcaneal angle, lateral talometatarsal angle, and calcaneal pitch were initially measured in both feet to evaluate alignment. Followup clinical and radiological evaluations were then performed at 12–18, 24–30, 36–42, and ≥48 months after RFO application. Repeated measures analysis of variance was used to evaluate significant differences. Results Significant improvements in all radiological indicators and significant progression of RCSP toward the corrective direction were observed after RFO application relative to baseline measurements. Conclusion According to our findings, RFO can induce significant improvements in calcaneus-related radiographic indices and subsequently improve talus-related radiologic indices.