Abstract: The Footscan^® was used to track and collect the plantar pressure data of 147 children aged 7-8 years when walking barefoot for three years. Ten children who kept flat feet for three years were screened out.The results were compared with the plantar pressure data of 10 normal foot children matched with age, height and BMI. Results show that: (1) during the three-year follow-up study, the arch index of flatfoot children showed an increasing trend. (2) M1-2 region and Heel region showed significant changes in normalized max force between flatfoot children and normal foot children, and flatfoot children showed an inflection point in the second year, which increased first and then decreased, while that of normal foot children increased significantly year by year. (3) the peak pressure in M3-5, MLA and LLA region of flatfoot children was significantly higher than that of normal foot children from the first year to the second year.

Key words: flatfoot, plantar pressure, children, longitudinal study, orthopedic shoes