Flat Feet: A Problem to Fix—or Simply the Way Your Feet Are?

Take off your shoes and stand normally.

Now look at the inside of your feet.

Can you see an arch between your heel and the ball of your foot? Or does almost the entire sole seem to touch the floor?

If it is the second, you may have flat feet, medically called pes planus.

And the first thing you should know is:

Having flat feet does not automatically mean something is wrong.

Flat feet are common. Many people have them throughout their lives, experience no pain, walk normally and participate in sports without needing treatment. The NHS specifically states that flat feet usually cause no problems and should not, by themselves, prevent normal activities or sports.

So the important medical question isn't simply:

“Are my feet flat?”

It is:

“Are my flat feet causing a problem—or is something changing in my feet?”

That distinction matters.

---

What exactly are flat feet?

The human foot is a remarkably complex structure of bones, joints, ligaments, tendons and muscles.

Along the inner side of the foot is the medial longitudinal arch—what most people simply call the foot arch.

When standing, this arch normally helps the foot adapt to the ground and manage forces during walking and running.

In a person with flat feet, the arch is low or may appear to disappear when weight is placed on the foot.

But there isn't one single type of “normal” foot.

Some people naturally have high arches. Some have moderate arches. Others have low arches.

Foot shape exists on a spectrum.

---

Flexible vs rigid flat feet: an important difference

Not all flat feet behave in the same way.

Flexible flat foot

In a flexible flat foot, the arch looks flat when standing but becomes more visible when weight is taken off the foot or during certain movements.

This pattern is common and may be completely painless.

Rigid flat foot

In a rigid flat foot, the arch remains flattened even when the foot is not bearing weight, and movement may be restricted.

A painful, stiff or rigid flat foot deserves more careful assessment because there may be an underlying structural problem. Clinical assessment of the foot and walking pattern helps distinguish different types.

---

Why do people develop flat feet?

There isn't one cause.

For some people, it is simply their natural anatomy.

Flat feet may also run in families. In other situations, changes in the tissues supporting the arch can occur with aging, injury, increased body weight or certain conditions affecting muscles, nerves or joints.

Children commonly appear to have flatter feet when young, and the arch usually develops as they grow. The NHS notes that arches commonly develop during childhood, generally between ages 3 and 10.

But there is another situation that deserves particular attention:

Your foot used to have an arch—and now it is becoming flatter.

That is different from having naturally flat feet all your life.

---

When flat feet develop in adulthood

An adult whose foot progressively becomes flatter may have a problem involving the structures that support the arch.

One particularly important structure is the posterior tibial tendon.

Think of this tendon as one member of the foot's arch-supporting team. It travels behind the inner ankle and helps support the foot during walking.

If this tendon becomes painful, weakened or dysfunctional, the arch can progressively collapse. This has traditionally been called posterior tibial tendon dysfunction (PTTD) or adult-acquired flatfoot; contemporary specialists may also describe the broader condition as progressive collapsing foot deformity.

Possible symptoms include pain or swelling around the inner ankle and arch, progressive flattening and difficulty with activities that load the tendon.

Unlike an asymptomatic flat foot you've had for years, a newly developing or progressively worsening flat foot should not simply be ignored.

---

Do flat feet cause pain?

Sometimes—but not always.

This distinction is extremely important.

A flat-looking foot may cause absolutely no symptoms.

When symptoms do occur, people may experience:

• Pain around the arch
• Pain around the inside of the ankle
• Foot fatigue after prolonged walking or standing
• Stiffness
• Difficulty with prolonged activity
• Recurrent foot or ankle problems
• Changes in walking
• Shoes wearing unevenly

Flat feet can also change how forces move through the lower limb, but finding a flat foot does not automatically prove that it is the cause of someone's knee, hip or back pain.

The entire lower limb needs to be assessed rather than blaming one anatomical feature.

---

Can flat feet cause heel pain?

Flat feet and heel pain can coexist, but again, one does not automatically prove the other.

A common cause of pain under the heel and arch is plantar fasciitis.

The plantar fascia is a strong band of tissue running along the bottom of your foot. Plantar fasciitis typically causes pain around the heel and arch, often worse during the first steps after sleep or rest.

So someone saying:

“My flat feet are causing my heel pain”

may actually need an assessment to determine what structure is producing the symptoms.

---

Do flat feet need to be corrected?

This is one of the biggest misconceptions.

A painless flat foot does not necessarily need to be “corrected.”

If you have always had flat feet, have no pain, walk comfortably and can perform your normal activities, treatment may not be necessary.

The goal of medical treatment should not simply be to make every foot look like an anatomical textbook.

The goal is to help the foot function comfortably and effectively.

That is an important difference.

---

Can exercises create an arch?

Exercise can improve the function of the foot and ankle, but patients should be cautious about claims that a few exercises will permanently “rebuild” every adult flat foot.

Depending on the problem, physiotherapy may work on:

Foot and ankle strength — improving the muscles and tendons that help support and control the foot.

Calf flexibility — tightness around the calf and Achilles region may influence foot mechanics.

Balance and control — helping the foot and ankle respond better during walking and activity.

Hip and leg strength — because your foot is part of a kinetic chain extending through the ankle, knee and hip.

For symptomatic adult-acquired flatfoot, physiotherapy may include mobility work, strengthening of the relevant tendon and calf/Achilles stretching.

The objective is usually better function and less pain, not simply creating a prettier-looking arch.

---

Do you need special shoes?

Not everyone with flat feet needs expensive footwear.

But if your feet are painful, footwear can make a meaningful difference.

A shoe that fits properly, provides appropriate support and is comfortable for your activity may reduce symptoms. For painful flat feet, clinical guidance commonly includes supportive footwear among conservative treatment options.

Very worn-out footwear may provide less support than it once did.

The “best shoe” is therefore not necessarily the most expensive shoe.

It is the shoe that suits your foot, symptoms and activity.

---

Do orthotics or insoles cure flat feet?

Orthotics are inserts placed inside shoes to alter support or redistribute load.

For some people with symptomatic flat feet, they can be useful.

But an important expectation needs to be clear:

An insole supports the foot; it does not necessarily permanently change the anatomy of an adult flat foot.

The NHS similarly notes that insoles and exercises may help symptoms such as pain and stiffness but do not necessarily change the shape of the foot.

That does not make orthotics useless.

If an orthotic helps you walk farther, exercise more comfortably or reduces pain, that can be a meaningful clinical outcome.

---

Do you need an X-ray or MRI?

Usually, not simply because your feet look flat.

A clinician can learn a great deal by examining:

• Your standing posture
• The shape of the arch
• Foot and ankle movement
• Where the pain is located
• Tendon function
• Strength
• Flexibility
• Balance
• Your walking pattern

Imaging may be considered when symptoms are significant, the deformity is rigid or progressive, an underlying structural problem is suspected, or the result would influence treatment.

So again:

We don't scan the shape. We investigate the problem.

---

When should flat feet be medically assessed?

You should consider an assessment if:

• Your feet have become painful
• The foot or ankle feels weak, stiff or numb
• Walking or balance is becoming difficult
• You repeatedly injure your foot or ankle
• One foot is changing more than the other
• You previously had an arch and it is now flattening
• The shape of the foot is progressively changing

These are also among the situations in which NHS guidance recommends seeking medical evaluation.

A sudden change after an injury, severe pain, inability to walk or obvious deformity warrants more urgent assessment.

---

Does flat foot require surgery?

Usually, no.

Most people with flat feet never need surgery.

For symptomatic flat feet, management may include appropriate footwear, activity modification, physiotherapy, exercises, orthotics or bracing depending on the underlying cause.

Surgery is generally reserved for selected patients with significant structural problems, progressive deformity or persistent symptoms despite appropriate non-surgical treatment.

So discovering that you have flat feet should not immediately create fear about surgery.

First understand the foot.

Then decide whether anything actually needs treating.

---

The CHAMPIONS Takeaway

Your feet are your body's connection with the ground.

But different does not automatically mean diseased.

A low arch without pain may simply be your natural foot shape.

A painful foot deserves attention.

And a foot whose arch is changing in adulthood deserves an explanation.

At CHAMPIONS – The Mobility & Vision Clinic, our philosophy is not to treat an X-ray, a scan—or the appearance of a foot.

We first ask:

Does it hurt?
Is it affecting function?
Is it changing?
And what is actually causing the problem?

Because the objective isn't to create a “perfect-looking foot.”

It is to help you stand confidently, move freely and stay active.

Reclaim your movement.

Live Strong Forever.

Medical Disclaimer: This article is intended for general educational purposes and does not replace an individual medical consultation, diagnosis or treatment. Seek appropriate medical attention for symptoms that are severe, persistent, progressive or concerning.

---

5. Frequently Asked Questions

-Are flat feet normal?

Yes. Flat feet are common, and many people with flat feet have no pain or limitation and require no treatment.

-Can flat feet be corrected in adults?

Treatment can improve pain, support and function, but exercises or insoles do not necessarily permanently change the anatomical shape of an adult foot. The goal is usually comfortable function rather than creating a particular arch shape.

-Should everyone with flat feet wear insoles?

No. Someone with painless, functional flat feet may need no treatment at all. Insoles may be useful when symptoms or a specific biomechanical problem justify them.

-Can flat feet cause knee pain?

Foot posture can influence lower-limb mechanics, but flat feet should not automatically be blamed for knee pain. Knee pain has many possible causes, so the knee, foot and overall movement pattern should be assessed when symptoms persist.

-Why has one of my feet suddenly become flatter?

A new or progressive flat foot in adulthood deserves evaluation. Problems affecting the posterior tibial tendon and other supporting structures can lead to progressive collapse of the arch.

-Do flat feet require surgery?

Rarely. Surgery is generally considered only for selected structural or progressive problems when appropriate conservative treatment has not provided sufficient relief.