Bone, Joint and Muscle Conditions


What Is Flatfoot?

Flatfoot. Photo by Vincent S. Mosca, MD.


Flatfoot is a common foot shape that doctors sometimes call pronated foot. When a person with flatfoot stands up, the arch in the middle of the foot disappears. The foot seems to lie flat on the ground.

There are three different types of flatfoot. Knowing which kind your child has helps you and your child's doctor decide if your child needs treatment and, if so, which kind of treatment.

  • Flexible flatfoot: Almost all children with flatfoot have what is called flexible, or hypermobile, flatfoot. This condition is not painful, causes no disability and does not need any treatment. It always affects both feet.
  • Flexible flatfoot with a short Achilles tendon happens very rarely in young children. It affects both feet, and may cause pain and disability.
  • Rigid flatfoot is the least common type. Rigid flatfoot most often shows up in people who have a problem with the bones in their feet (tarsal coalition). About one in four people with rigid flatfoot has pain and disability. About half of the time, rigid flatfoot affects both feet.

Flatfoot in Children

Almost all babies are born with flatfoot. Studies estimate that 80% to 90% of babies born in North America have flatfoot. Studies in other countries have found similar numbers. Most of these babies have flexible flatfoot.

Children often outgrow flatfoot naturally. But at least 20% of adults in North America have flatfoot. About 25% of these adults have flexible flatfoot with a short Achilles tendon and 9% have rigid flatfoot.

Flatfoot at Seattle Children's

Flatfoot is one of the conditions treated by the experts in our Foot and Ankle Deformities Program.

The former director of our Department of Orthopedics, Dr. Lynn T. Staheli, produced groundbreaking research that changed the way doctors worldwide understand and treat flatfoot.

Research led by Dr. Staheli showed that, in most children, flatfoot is a common shape that does not cause pain or disability. Most children naturally develop arches in their feet during their first decade of life.

This work prompted doctors at other medical centers to do research that showed that special shoes and shoe inserts do not help create an arch in a flatfoot. These findings ended the use of expensive treatments that do not work.

Further, researchers at Children's Hospital found that shoes once used to treat flexible flatfoot made some of the children who wore them feel abnormal and hurt them psychologically.

For the rare cases when surgery is needed, doctors at Seattle Children's developed the most common operation now used nationally to correct severe, painful flatfoot with short Achilles tendon in adolescents. Doctors use this operation only when other more conservative treatments do not work.