When the tarsal joint (that forms the arch) falls, some kids, unconsciously, perceive the danger of it and try to prevent the higher medial arch (the big toe side arch) from falling by curling the toes in while walking. This behavior makes the kids walk on the lateral side of the foot where the arch (pinky toe side arch) is low. This behavior twists their legs inwardly and can develop another kind of structural problems.
Solution: By supporting the tarsal joint with the proper orthotics that align the anklebones can prevent and improve this condition.