Flat feet once were considered enough of a disability to bar people from entering the armed forces, but now are considered a normal variant of human foot shape. Adults may develop flat feet called pes planovalgus or fallen arches, or in some cases, children simply don’t develop an arched foot. Common thinking held that corrective shoes in children might develop an arch, but studies among people who regularly go barefoot suggest shoes on young children are more likely to promote flat feet rather than to cure them.

Most infants begin with flat feet, which should be no cause for concern among parents. Arches develop as children learn to walk and as less baby fat covers the feet. For many children who don’t develop an arch, this poses no problem, however, in some cases, flat feet can be associated with other feet problems. In particular, children who have anklebones that lean inward may require corrective shoes. Flat feet that are inflexible and painful may result from a condition called tarsal coalition.

Tarsal coalition occurs when two bones in the foot fuse together. This results in a highly inflexible foot and pain during walking, and shoes with arches may make the condition even worse. Children who exhibit flat feet and complain frequently of foot pain should be evaluated by a doctor, and normally undergo surgical treatment in their pre-teen years to correct the fusing. Surgery needs to be undertaken while the foot is still growing in order to be effective.

Flat feet which develop in adulthood may be called fallen arches. This is a typical occurrence in women who are pregnant, of those who are carrying more weight. Adult-acquired flat foot tends to be permanent, but may not be related to any specific complications to the feet. When flat feet do result in painful walking, using specially designed orthotics in shoes and performing foot exercises often treats the condition. Surgery can correct a flat foot but it is seldom the treatment of choice.

While flat feet were once considered a sign of poor health, the opposite may in fact be true. Most top track stars have very flat feet. Also, people with a higher arched foot are four times as likely to turn or sprain an ankle than is a person with flat feet. Thus there may be some benefits to the condition. Flat feet are no longer a reason to be excused from army service, and in many cases, create no problems for the person who has them.