Flat Foot

Structural and Postural Conditions· Also known as: flat feet, fallen arches, dropped arches, pes planus, pes planovalgusUpdated Oct 2026

Reviewed by Andrew Schox, BSc(Hons) PGradDipPod MPod, October 2026

At a Glance

Flat foot means the arch on the inside of your foot is low or missing, so the sole touches the ground when you stand. It is common: about 90 per cent of 1 year olds have flexible flat feet, and up to 20 per cent of adults do. Many people have no symptoms at all. When there are symptoms, they include foot, shin or calf pain and tiredness after activity. In children it is usually a normal stage of development, and over 95 per cent of children aged 1 to 5 years grow out of it. In adults, a foot that is changing shape or becoming painful needs checking.

What is it?

Flat foot (pes planus) means the arch on the inside of your foot is low or missing. When you stand, the sole of your foot comes into contact with the ground. It can be flexible or fixed (rigid), and it can be part of normal development, be present from birth, or develop later in life.

In a flexible flat foot, an arch appears when you stand on tiptoe. This is the most common type in children, and it is not a disease. A rigid flat foot, where the arch doesn't come back, is rare in children and may have an underlying cause.

Who does it affect?

How common flat foot is depends on age and on how it is measured. Overall, about 15.6 per cent of people have it. Flexible flat feet are present in about 90 per cent of 1 year olds and in up to 20 per cent of adults.

Flat feet are normal in children up to about eight years of age. Most children aged 1 to 5 years have them as part of normal growth. Flat feet are found more often in boys, in children under 6, and in children who are overweight. They are also linked with very flexible joints, wearing sports shoes, living in a city and doing less exercise. These links show patterns, not proof that any one of them is the cause.

Adults can also develop flat feet later in life, which is a different situation from the normal flat feet of childhood.

Signs and symptoms

The main sign is a low or missing arch when you stand. Flat feet don't always cause symptoms, and in some people the arch stays low into adult life without any pain or problems.

When there are symptoms, they can include:

pain in the foot
pain in the shins or calves
pain or swelling on the inside of the ankle
uneven wear on your shoes
pain or tiredness in the feet, legs or ankles, especially during or after activity

In adults, flat foot that develops later can bring increasing pain on the inside of the ankle and in the arch when you are active, along with a change in the shape of the foot.

Only a small number of children with flat feet have any pain (fewer than 2 per cent).

What causes it?

In young children, flat feet are usually part of normal development. Babies and young children have a soft fat pad under the arch. Their joints and ligaments (the bands that hold bones together) are also more flexible, which lets the foot flatten.

Other causes and contributors include:

a family history of flat feet
tight muscles or tendons
carrying extra weight
conditions such as Ehlers-Danlos syndrome, cerebral palsy, juvenile arthritis and muscular dystrophy

In adults, flat foot that develops later can come from tibialis posterior tendon dysfunction (a problem with a tendon on the inside of the ankle). The tendon starts to wear well before any symptoms appear, which is why noticing early changes matters.

How is it diagnosed?

Your podiatrist will ask about your pain, your shoes, any injuries and any recent change in the shape of your feet. They will look at your feet while you stand and while you walk. They will usually ask you to stand on tiptoe: if an arch forms, the flat foot is flexible.

For children, your podiatrist may use a scoring system that rates foot shape. There is no single agreed set of rules for diagnosing flat foot in children, and each scoring method has limits. They will also check for signs of very flexible joints or muscle or connective tissue conditions.

X-rays and other scans are not usually the first step. A standing X-ray can be useful when the diagnosis is unclear, or in adults whose foot shape is changing.

Treatment

If your flat feet aren't causing any problems, you don't need treatment. This applies to adults and children. Flexible flat feet in children don't routinely need treatment either.

Looking after it at home

For children, the best step is reassurance. Flat feet are normal in young children, and arches usually develop between 3 and 10 years of age.

If your flat feet cause symptoms, options include more supportive shoes and, if you are carrying extra weight, losing some. Check your feet often for changes or increased pain. If you are pregnant, wear supportive shoes.

Treatment from your podiatrist

Insoles (also called orthoses or arch supports) can improve the position of the foot bones and the way pressure moves through the foot in flexible flat foot. How much they ease pain or help everyday function isn't yet clear. Use arch supports if your podiatrist advises them.

Exercise can also help. In flexible flat foot, exercise improved how much the inside of the arch drops when you stand, and it had the largest effect of the options compared. Short foot exercises are one type of exercise your podiatrist or physiotherapist may suggest. Their benefit is clearest in programmes that run for longer than 6 weeks, although results across studies have been mixed.

Other options

If first-line care isn't enough, your podiatrist or GP may refer you to a specialist. This is usually considered if you have:

a rigid flat foot, or one that is very painful
significant pain at rest or at night
significant trouble with everyday activities
a flexible flat foot with few symptoms that hasn't improved after more than 6 months of treatment

For children, a rigid flat foot, or symptoms that continue despite arch supports, should lead to an assessment by an orthopaedic specialist (a bone and joint doctor). For adults whose flat foot has developed later, the stage of the problem guides which treatments suit you, from non-surgical care to surgery.

Surgery

Surgery for ordinary flexible flat foot is a decision for a specialist. The surgical results available are for a rare, rigid type present from birth, called congenital vertical talus, so they don't apply to ordinary flexible flat foot. In children with congenital vertical talus, the foot bones slipped out of position again on X-ray in 19.3 per cent of cases after surgery, and 7.8 per cent needed another operation. If surgery is suggested for you or your child, ask the specialist about the risks before deciding.

Recovery

For most children the outlook is good. Over 95 per cent of children aged 1 to 5 years grow out of flat feet and develop a normal arch. By ten years of age, only about 4 per cent still have a flat foot that persists or is getting worse. After age ten, a flat foot can become more fixed and stiff.

In adults, a flat foot caused by tibialis posterior tendon dysfunction tends to get worse over time. It can cause pain, weakness and changes in foot shape if it isn't managed. In the final stage, left untreated, the ability to walk can be lost. This is why new pain on the inside of the ankle, or a foot that is changing shape, is worth having checked early. Treatment is chosen to suit the stage of the problem.

Preventing it

No proven way to stop the arch from flattening is known. Normal flat feet in young children aren't something to prevent, because most grow out of them.

To look after your feet, check them often for changes or increased pain. Wear supportive shoes, particularly if you are pregnant. If your podiatrist advises arch supports, use them.

When to see a podiatrist

Book an appointment if

Your flat feet cause pain or tiredness in your feet, legs or ankles, especially during or after activity, or your shoes are wearing unevenly. Also book if you have a flexible flat foot with few symptoms that hasn't improved after more than 6 months of treatment. For a child, book if they begin to walk oddly or clumsily, such as on the outer edges of their feet, or complain of calf or muscle pain around the feet.

Seek prompt assessment if

These signs need attention without delay.

If your foot is red, hot or swollen and you have diabetes or have had an injury, see your GP or another doctor today, so a condition called Charcot foot can be ruled out. If your foot has suddenly become flat after a recent injury, see your GP or another doctor today, because a fracture can look like a sprain. If your foot shape is getting worse, see your GP or another doctor today. If you have foot pain together with night sweats, a fever or weight loss, see your GP or another doctor today. If your GP can't see you today, go to an urgent care clinic or an after-hours GP.

See your GP soon if your flat feet are new, affect only one foot, or are painful, stiff, weak or numb. Also see your GP soon if you have a burning feeling in your foot, frequent injuries, trouble walking or balancing, a limp, or new pain on the inside of your ankle with new flat feet.

For a child, see your GP soon if their flat foot is rigid, very painful, still causing symptoms despite arch supports, or painful or stiff in an older child. See your GP soon too if their arches were normal and flat feet developed later, or if a child under 8 keeps falling or has trouble walking.

Frequently asked questions

Can flat feet cause knee or back pain?

They can. For some people, flat feet bring pain in the foot, ankle, knee and low back. Many people with flat feet have no symptoms at all. If you have pain in these areas, your podiatrist can look at how your feet are working and whether treatment is worth trying for you.

Are fallen arches the same as flat feet?

Yes. Fallen arches, dropped arches, flat feet and pes planus all describe a low or missing arch on the inside of the foot. Your podiatrist may call it flexible if the arch appears when you stand on tiptoe, or rigid if it stays flat. Which type you have helps decide what care suits you.

Do I need to see someone if my flat feet don't hurt?

Not usually. Painless flat feet that aren't causing problems need no treatment. Keep an eye on your feet, though, and check them often for changes or increased pain. If they start to hurt or change shape, or the flat feet are new or only on one side, have them looked at.