Most adult feet have an arch along the inside edge of the foot. Flat foot is when this arch is apparently absent or reduced in standing. The arches may ‘appear’ when your child is sitting, when the big toe is bent backwards or if your child stands on tiptoe. Before the age of 3 all children have flat feet, as the arch on the inside of the foot does not begin to develop until after this age. Even in older children flat feet do not usually cause any problems.
Leaflet produced by Association of Paediatric Chartered Physiotherapists