The arch is the area on the inside of the foot that does not touch the ground. It can vary in height from high to very low and this variation is usually completely normal.
The arch in young children starts low and should develop between the ages of 3-10yrs. However, in some cases this will remain low and will not affect development or function into adult life and is usually pain free (asymptomatic).
People with a low or absent arch are said to have flat feet, sometimes referred to as ‘fallen arches’, although the term is misleading as a flat arch profile is completely normal for some.