Flat Feet (Pes Planus)

Pes planus, often called “flat feet,” refers to a condition where the medial (middle) arch of the foot is flattened. This is quite common, particularly in young children. It can spontaneously improve with growth and strengthening but persists in up to 20-25% of adults.

The condition is caused by flexible ligaments within the foot and ankle at a young age. The overly flexible ligaments allow the heel to tip outward, which results in the inside of the foot rolling into the floor (pronating) and flattening the arch.

There are 2 types of flat feet. The most common type is flexible flat feet, which is due to the flexibility of the ligaments. The less common type is rigid flat feet, which is typically due to bone alignment where some of the bones of the foot fail to separate before birth. A person with flexible flat feet will have arches present when sitting or when standing on their tiptoes, but a person with rigid flat feet never has arches present in their feet.

Some people do not have any symptoms with their flat feet. However, others complain of pain with prolonged walking or activity and often children with flat feet have a hard time keeping up with their peers when running for long periods of time. Pes planus can typically be diagnosed with an exam alone, but x-rays can be beneficial if your child is having significant pain or if you suspect they have a rigid flat foot. Occasionally, flexible flat feet will signal a hypermobile condition where most of the ligaments in the body are overly flexible.

Treatment varies based upon the type of flat feet and whether they are causing pain or other symptoms. For children with flexible flat feet, treatment consists of Achilles tendon stretching and occasionally some physical therapy to work on stretching and overall strengthening of the legs. There are various types of orthotics (shoe inserts) that your child can wear to support the feet throughout the day. It is important to note that frequent use of shoe inserts in children with flat feet only works to support the feet while wearing the inserts—they do not result in a long-term change in alignment. Because of this, when your child is barefoot, they will still appear to be flat-footed.

For children with rigid flat feet who continue to have significant pain after physical therapy and inserts, your orthopedist may recommend surgical correction of the foot alignment. Surgery is uncommon and the last consideration in children with flexible flat feet. Once we have found the right option to support the feet throughout the day, most children are free to be active in whatever they choose to do.

For additional information specific to flexible flat feet, please watch this video on OrthoKids, a site created by the Pediatric Orthopedic Society of North America.