There are several types of flat feet that generally develop at different ages:
Children normally have flat feet for about the first six years of their life because it takes time for bones to mature and develop strong arches. About 1-2% of all children don’t outgrow their flat feet.
Although it’s rare, children may be born with inherited conditions that cause flat feet.
Flexible flat feet begin in childhood or adolescence and continue through their adult years. When you have flexible flat feet, your feet are flat when you’re standing but the arches return to normal when they don’t have to bear your weight. Flexible flat feet worsen over time, leading to torn and inflamed tendons and ligaments.