Everyone’s feet are different, so whether you have a contour on the bottom of your foot may not seem important. But foot arches help distribute your weight, keep you balanced and act as a shock absorber.
Not all arches are created equal, and it’s natural for arches to flatten slightly when the foot is on the ground and restore their curve when off the ground. However, if the entire sole of your foot is flat on the ground when you stand, you may have flat feet, also known as pes planus.
Flat feet are common — nearly 40% of the population may have some degree of pes planus — and it does not always cause a problem. But if you or your child experience pain related to flat feet, there are ways to treat it.
What are flat feet?
People who have flat feet don’t have a medial longitudinal arch, which typically runs from the inner edge of the heel to the ball of your foot. Several bones make up the arch, and those bones are supported by ligaments and tendons. When the supportive tendons are loose, the arch can’t maintain its rounded shape.
There are two types of flat feet:
- Flexible: There is no arch when you stand or walk, but an arch appears when you sit or are standing on your tiptoes. Flexible flat feet tend to be milder and do not typically cause severe pain or affect your body’s alignment.
- Rigid: There is never an arch. Rigid flat feet are more likely to cause pain or be linked to a more severe underlying issue.
What causes flat feet?
You can be born with flat feet or develop one or both flat feet at any age. Pes planus often runs in families. If you’ve always had flat feet, possible causes include:
- Deformed bones in the feet
- Genetic disorders that affect connective tissues, such as Ehlers-Danlos syndrome or Marfan syndrome
- Tarsal coalition, a rare condition in which two or more bones in the foot grow or fuse together
- Tight Achilles tendons, felt on the back of your ankle just above your heel
Flat feet that develop later in life tend to be the result of age, wear and tear, or injury.
Flat feet in children
All babies and toddlers have flat feet because the arches take time to fully develop. Infants have a fat pad under their arch to protect it during early childhood. As your child grows, the tissues and tendons in the feet tighten and form the arch. Some children will have arches in place at age 2 or 3, and most develop them by age 6. Some people will never develop arches.
Flat feet do not typically cause pain or problems in children. But if your child experiences foot, ankle or lower leg pain, consult their primary care physician. Flat feet are usually diagnosed by pediatricians after observing a child walking, asking questions and evaluating wear patterns in their everyday shoes. They may order imaging tests if the pain is severe or they suspect an underlying condition.
Flat feet in adults
Flat feet can develop at any age. If you haven’t always had fallen arches, your risk of developing them increases with:
- Age
- Diabetes
- Foot and ankle injuries
- Obesity
- Rheumatoid arthritis
Acquired flat feet are typically the flexible type. Since most people don’t usually study their foot shape later in life, you may notice other signs of flat feet, such as:
- Achy or tired feet after long periods of standing
- Changes in appearance and flexibility of your toes
- Pain in your ankles, legs or back
- Swelling along the inside of the foot or ankle
You can also check for flat feet by performing the “wet foot” test. Wet your feet and stand on a flat, dry surface. If your footprint shows the entire sole of your foot, with no pronounced curve on the inner edge, you likely have flat feet.
Treatment for flat feet
Not everyone with flat feet needs treatment. If your fallen arches aren’t causing pain or symptoms, there’s no need to do anything. If you are having symptoms, treatment may depend on age, severity and whether your flat feet are flexible or rigid.
Treatment for mild symptoms and flexible flat feet may include:
- Arch support (orthotics) for your shoes
- Stretches to loosen your calves and tendons
- Special shoes with built-in arch support
If you have severe symptoms associated with flat feet, treatment often depends on the underlying cause and may include:
- Rest, for flat feet associated with an injury
- Casting, for flat feet caused by tarsal coalition
- Surgery, which can repair tendons, restore an arch by transferring a tendon or fuse joints into the correct position
Treatment for flat feet is individualized so getting evaluated by a health care professional is always a good idea.
