The Relationship between the Flexible Flatfoot and Plantar Fasciitis: Ultrasonographic Evaluation

Background: The purpose of this study was to investigate the relationship between flexibleflatfoot and plantar fasciitis.Methods: Twenty-three subjects with flexible flatfoot and 23 subjects with normalarched feet were enrolled. Footprint analysis was used to evaluate the footconditions in both groups to calculate the individual arch index. We comparedthe sonographic images of plantar fascia in the flexible flatfoot groupwith the normal arch group using high-frequency ultrasound.Results: The analysis results indicated that the thickening of the plantar fascia in theflexible flatfoot group was significantly different from the normal archgroup. In the flexible flatfoot group, 10 of 23 patients (43.4%) had plantarfasciitis, but only two subjects (8.7%) in the normal arch group had plantarfasciitis.Conclusions: There was a higher incidence of plantar fasciitis in the flexible flatfoot groupthan the normal arch control group in this study.