People with flatfeet make up about 20 per cent of the adult population. A flat foot deformity is defined as a foot lacking the normal arch of the foot and a sinking inward of the heel. A good indication of if you have flat feet is to look at your footprint after walking in water–the lesser the curve on the instep, the flatter your foot is. Infants are born with flat feet and arches do not typically fully develop until around age five. Flat feet are more prevalent in males and the obese population. Normally flat feet are very flexible and the tiny foot muscles work well.
Rarely do people with flat feet have foot pain because of the shape of their feet, however there is a small group of people (less than one per cent) who present with a stiff flatfoot and a short achilles tendon which have an increased prevalence of pain and dysfunction in adulthood.
Often flat feet are brought to an orthopedist’s attention in childhood or adolescence, primarily out of concern for cosmetic reasons, future pain or dysfunction in adulthood. However, the latest evidence suggests that because only a small portion of the flat foot population has pain no treatment is necessary, orthotics or otherwise. If a child does present with pain, then they do need to be treated but it is important to find out the cause of the pain. In a flexible flat foot when long term orthotics are indicated, over the counter orthotics helping to create an arch are sufficient. Custom orthotics should only be utilized when over the counter orthotics or other nonsurgical treatments do not work. Orthotics correcting the arch for a rigid flatfoot or for a flexible flatfoot with a shortened achilles tendon will actually exacerbate the problem. Conservative treatment for a shortened achilles tendon typically involves a specific daily stretching program.
In the very rare case where pediatric surgery for flatfeet is indicated, standards are strict for eligibility and prior to surgical correction all other conservative treatments must be attempted. Soft tissue corrections, like achilles tendon lengthening, are rarely successful. Ankle fusion to a more neutral position will speed arthritis and decrease overall function and mobility. Restriction of the primary joint causing the flat foot, called an arthroereisis, shows poor promise and is not well studied. Osteotomy, or the lengthening or shaving of certain foot bones, is the gold standard treatment and has excellent outcomes with well-trained surgeons.