What causes flat feet?
Most flat feet are caused by loose joint connections and baby fat between the foot bones. These conditions make the arch fall when your child stands up. This is why you sometimes hear flat feet called "fallen arches." The feet may look like they have arches when your child is sitting or when the big toe is bent backward, but the arch flattens when the child puts weight on the foot.
Rarely, flat feet can be caused by foot bones that are joined together.
Written by familydoctor.org editorial staff