Flat Feet (Adult Acquired Flatfoot)

Flat feet is a foot shape in which the arch along the inner side of the foot is low, or has flattened, so more of the sole rests on the floor. In adults, new or worsening flat feet with pain is a medical problem worth assessing. This page covers causes, stages, treatment and care, including treatment in turkey.

What are flat feet?

The arch is the curved span between the ball of the foot and the heel. When you stand, a healthy arch rises a little off the ground. With flat feet, that span sinks. Doctors call the condition pes planus, and when it develops later in life they call it adult acquired flatfoot.

It helps to separate two ideas. Some people are born with low arches and have flexible, pain-free feet for life. Others, usually after 40, slowly lose a previously normal arch because a tendon or ligament gives way. The second group is the main focus here.

Who gets flat feet?

Low arches are common, and most children are born with flat feet that develop an arch by about 6 to 10 years of age. A minority keep a low arch into adult life without any trouble. Adult acquired flatfoot is seen more often in women, in people over 40, and in those with obesity, diabetes, high blood pressure or inflammatory arthritis.

Past injury also matters. A fracture or sprain of the ankle or midfoot, or long years of work on hard floors, can place extra demand on the arch-supporting structures and bring on flat feet later.

How serious are flat feet?

A flexible flat foot that causes no pain is generally harmless. A painful flat foot that is getting flatter is different, because the tendon holding the arch may be failing. Left alone, the foot can stiffen in a collapsed shape and the ankle can start to wear. Early assessment keeps more treatment choices open.

Most adults with painful flat feet never need surgery. Even so, knowing which stage you are at is the single most useful piece of information for planning care.

How this page is organised

The sections below describe foot anatomy, symptoms and causes, then the 4 stages, tests and look-alike problems. We then cover insoles, exercises and self-care before moving to surgery, the decision to operate and the pathway for treatment abroad. Complications, prevention, outlook and common questions come last. For wider context, see our foot and ankle overview.

The arch of the foot is held up by bones shaped like a vault, by strong ligaments and, above all, by a tendon that runs behind the inner ankle bone. In flat feet this support system stretches or fails, so the vault sags and the heel drifts outward. Knowing the parts makes the symptoms easier to follow.

How is a healthy arch built?

Each foot has 26 bones. The ones that matter most for the arch are the heel bone (calcaneus), the ankle bone (talus), the boat-shaped navicular on the inner side and the 3 cuneiform bones in front of it. Together they form a curved vault rather than a flat plate.

The spring ligament is a thick band under the inner midfoot that cradles the head of the talus like a hammock. The plantar fascia, a broad band along the sole, ties the heel to the toes and tightens the arch when the big toe lifts as you push off.

What does the posterior tibial tendon do?

The posterior tibial tendon starts in a deep calf muscle, passes behind the inner ankle bone (the medial malleolus) and fans out under the navicular. It acts like a rope that pulls the arch up and turns the heel slightly inward every time you push off. It is the main dynamic stabiliser of the arch.

Because it is loaded with every step, this tendon is under heavy stress. It also has a relatively poor blood supply just behind the ankle bone, which helps explain why it is the usual site of trouble.

What changes in adult acquired flatfoot?

When the posterior tibial tendon becomes inflamed or torn, it can no longer hold the arch. The spring ligament then stretches, the talus slips inward and downward, and the heel tilts outward in a position called hindfoot valgus. The front of the foot rotates outward, which is why the toes seem to point away from the body line.

Over time the outer ankle bone can press against the heel bone, a problem known as sinus tarsi or subfibular impingement, and the inner side of the ankle joint can be overloaded. In long-standing cases the joints stiffen and the deformity becomes fixed.

Doctors divide adult acquired flatfoot into 4 stages according to how far the deformity has progressed and whether the foot can still be corrected by hand. The stage is the most important factor in choosing between non-surgical care and the type of operation. It does not always advance in a straight line, and many people stay at stage 1 or 2 for years.

What are the 4 stages of adult acquired flatfoot?

The widely used Johnson and Strom system, later expanded, describes the following stages. Imaging and a standing examination place you within it.

Why does flexibility matter?

A flexible flat foot can be pushed back into a normal shape by the examiner, which means the joints are still healthy and the arch can be rebuilt without fusing them. A rigid flat foot cannot, so a surgeon usually needs to fuse certain joints to hold the foot in a better position. This is the reason many surgeons describe flexible and rigid flat feet as separate problems.

Are there other types of flat feet?

Yes. Fallen arches, the everyday name for this shape, come in several forms. Flexible flat feet that begin in childhood are the most common and usually cause no pain. Rigid flat feet in children may come from a tarsal coalition, in which two foot bones are joined by bone or fibrous tissue. Neurological conditions, such as cerebral palsy or Charcot arthropathy in diabetes, can also produce a collapsed arch.

These types need a different approach, and a correct diagnosis matters. If you are not sure which type applies to you, a review of your scans can often clarify it before any decision is made.

Flat feet in adults are diagnosed by a physical examination while you stand and walk, supported by weight-bearing X-rays and sometimes ultrasound or MRI. The key aim is to decide whether the posterior tibial tendon is working, whether the foot is still flexible, and whether the ankle joint is healthy. Good information at this point guides the whole plan.

What does the clinical history cover?

Your clinician will ask when the arch changed, whether one or both feet are involved, and where the pain sits. They will ask about injuries, work on hard surfaces, sports, footwear and any earlier injections. They will also check for diabetes, rheumatoid arthritis, high blood pressure, smoking and body weight, because these affect both the cause and the healing.

What happens during the examination?

You will be viewed standing from behind and from the side. The examiner looks for hindfoot tilt, a flattened arch, the "too many toes" sign and swelling behind the inner ankle bone. Tenderness is checked along the course of the tendon.

Strength is tested with the single-leg heel raise. In a healthy foot, the heel lifts and the heel turns inward. When the tendon fails, the heel stays tilted or cannot lift at all. The examiner also checks whether the heel corrects by hand, and how tight the calf is.

Which imaging is used?

Weight-bearing X-rays of the foot and ankle are the first test, because a flat foot looks different when loaded. They show arch height, the alignment of the talus and navicular, and signs of arthritis. An ankle view shows whether the ankle joint is tilting.

MRI shows the tendon directly, including splits, thickening, and the spring ligament. Ultrasound can also show tendon inflammation and fluid. CT is useful when joints are stiff or a coalition is suspected. Not everyone needs every scan.

What should you prepare for a remote review?

For an online review, gather recent weight-bearing X-ray images in digital form (not only the report), any MRI or ultrasound, a list of medicines, and a summary of treatment tried so far. A few clear photographs of both feet from behind and from the side, taken while standing, add very useful information. Our guide to medical record review explains how this works.

Most adults with painful flat feet are treated without surgery first, and early stages often settle with supportive footwear, bracing and a tailored exercise plan. The aim is to rest the overloaded tendon, hold the arch up while it recovers and build the calf and foot muscles that share the work. Treatment is usually tried for at least 3 to 6 months.

What is the first step?

Activity is adjusted rather than stopped. High-impact work such as running, jumping and long hours on hard floors is reduced for a period, while low-impact options such as swimming and cycling continue. Ice and pain-relieving medicines can calm flare-ups. A simple walk to build confidence usually remains possible.

Weight management is helpful because every extra kilogram adds load to the arch with each step. Even a modest loss often eases the inner ankle pain.

Which footwear and insoles help?

Shoes with a firm heel counter, a stiff midsole and a roomy toe box give the foot a stable base. Soft, flexible shoes and flat sandals tend to make the problem worse. Supportive insoles, either ready-made or custom, raise the arch and share load across the sole.

Custom orthoses are usually moulded from the foot and may include a medial heel wedge and arch support. Studies suggest they reduce pain and slow progression in early stages, although they do not rebuild a torn tendon.

When is a boot or brace needed?

For a flare-up in stage 1 or 2, a walking boot for 4 to 8 weeks gives the tendon complete rest. After that, many people move to a lace-up ankle brace or a custom ankle-foot orthosis that wraps around the ankle and supports the hindfoot. Braces are the main non-surgical option when surgery is not suitable, such as for older or medically frail patients.

What does physiotherapy include?

A physiotherapist will check calf flexibility and strength, and teach a progressive programme. This often includes calf stretching, tibialis posterior strengthening with resistance bands, balance training and foot-control exercises. Programmes typically run for 6 to 12 weeks, then continue as home exercise.

Are medicines and injections useful?

Simple analgesics and anti-inflammatory medicines (NSAIDs) may reduce pain and swelling, taken as advised by a doctor. Corticosteroid injections around the posterior tibial tendon are generally avoided, because they may weaken the tendon and lead to rupture. If an injection is suggested, ask about the risks and alternatives.

What does the evidence say?

Evidence for early-stage care is encouraging but not strong, with small studies showing that bracing combined with exercise can relieve pain in a large share of people. Many people avoid surgery for years. What the evidence does not show is that insoles alone can reverse an established collapse, so regular review is useful.

When non-surgical care does not control symptoms, flat feet surgery rebuilds the arch by repairing or replacing the failing tendon and correcting the bones and ligaments. The right operation depends on the stage, the flexibility of the foot and your general health. No single procedure suits everyone, and surgeons usually combine several steps.

What is flatfoot reconstruction?

Flatfoot reconstruction is the standard surgery for painful, flexible flat feet that have not improved with bracing. It is described in more detail on our flatfoot reconstruction procedure page. You can also read how flatfoot reconstruction in turkey is organised.

The operation is built from several parts, chosen to suit your foot. Most patients need 2 to 4 of them.

• Tendon transfer: a healthy tendon, often the one that bends the toes (flexor digitorum longus), is moved to take over from the damaged posterior tibial tendon.
• Heel bone osteotomy: the heel bone is cut and shifted inward so the heel sits back under the leg, which reduces strain on the repair.
• Lateral column lengthening: the outer side of the foot is lengthened with a bone graft or wedge to rotate the forefoot back into line.
• Spring ligament repair or reinforcement: the stretched ligament under the inner midfoot is tightened or reinforced.
• Calf lengthening: a tight gastrocnemius or Achilles tendon is released to reduce pressure on the arch.

When is joint fusion needed?

For a stiff, rigid foot (stage 3), the joints are no longer healthy enough to be rebuilt and are instead fused. A triple arthrodesis, or a more limited fusion, holds the hindfoot in a corrected position. Fusion reduces pain and gives a stable foot, at the cost of some flexibility in the joints that are joined.

What if the ankle is involved?

In stage 4, the ankle itself has started to tilt. Options include fusion of the ankle, sometimes together with the hindfoot, or realignment combined with total ankle replacement, a procedure also offered as total ankle replacement in turkey. Ankle fusion is also discussed on the ankle fusion page.

Are there minimally invasive choices?

Some surgeons use ankle arthroscopy to look inside the joint or clear inflamed tissue, and certain smaller procedures use small incisions. These are suitable for selected, less severe cases. A small implant placed in the hindfoot (a subtalar spacer) is occasionally used in flexible deformity, though it is not suited to every foot.

How do the options compare?

For an overview of the specialty, see foot and ankle surgery. For costs, read our flatfoot reconstruction cost guide.

Not every case of flat feet can be prevented, because inherited foot shape, age and some medical conditions play a part. Even so, protecting the posterior tibial tendon and the arch reduces the chance of a painful collapse, and it can slow progression if it has started. The measures below are practical and low-cost.

How can you protect the arch day to day?

Wear supportive, well-fitting shoes with a firm heel and a stiff sole, and replace them when the inner heel is worn down, usually after 6 to 12 months of regular use. Avoid prolonged barefoot walking on hard surfaces. Rotating shoes and using a cushioned insole can reduce repetitive load on the tendon.

What about weight and general health?

Keeping a healthy weight cuts the load on the arch with every step. Good control of blood sugar and blood pressure protects tendon blood supply. Stopping smoking improves tendon healing. If you have rheumatoid arthritis, regular review of your inflammatory disease also helps protect the foot.

Which habits help the foot and calf?

Regular calf stretching keeps the Achilles tendon from tugging the heel outward. Strengthening the foot and ankle muscles, balance work and gradual increases in walking or running volume all protect the tendon. A sensible rule is to raise weekly activity by no more than about 10% at a time.

Should you act early on symptoms?

Yes. Early inner ankle pain that lasts more than 2 to 3 weeks deserves attention. Early supportive care when the foot is still flexible gives the best chance of keeping the arch without surgery. A visit to a foot specialist when you first see your arch dropping is far easier than waiting for a fixed deformity.

What cannot be prevented?

Age-related tendon changes, family history and a naturally loose-jointed foot cannot be altered. What you can do is reduce the extra load and notice early signs. Many people with these risk factors keep a comfortable foot for life.

Treating other foot problems promptly, such as hallux rigidus or ankle osteoarthritis, also helps because pain in one part of the foot changes how you walk and loads the arch differently.

The outlook for flat feet is generally good, and many adults stay active with bracing, insoles and exercise, while those who need surgery usually report less pain and better walking. The path depends on the stage, your general health and how closely you follow the rehabilitation plan. Realistic expectations help you plan well.

What is the natural course without surgery?

Mild flexible flat feet may stay stable for years. Painful posterior tibial tendon dysfunction can progress, though not always. Some people hold at stage 1 or 2 for a long time with a brace, while others slowly stiffen. Because it cannot be predicted for each person, periodic review makes sense.

What is recovery after flatfoot reconstruction like?

Recovery is gradual. A typical pattern is a cast or splint for about 2 weeks, then a boot with no weight on the foot for around 6 weeks. Weight-bearing in the boot usually starts between 6 and 8 weeks, and the move into supportive shoes happens around 10 to 12 weeks. Swelling can last for 6 months or longer.

Physiotherapy begins once bones have started to heal. Your surgeon will set the timetable, as it differs between a tendon transfer and a fusion.

When can you return to work and driving?

Desk work is often possible after around 6 to 8 weeks with the foot elevated. Driving depends on which foot was operated on and on being off strong pain medicines, often 8 to 12 weeks for the right foot. Jobs that need standing or climbing may need 4 to 6 months before full return.

What about sport and long-term results?

Walking, cycling and swimming are usually back within 4 to 6 months. Running and impact sport are often discussed from about 6 to 12 months, and some patients choose not to return to high-impact activity. Most people report good pain relief and function after reconstruction, though the foot may feel slightly stiffer.

Long-term, a corrected foot can last many years, but arthritis in neighbouring joints can still appear. Keeping to your exercises, supportive shoes and a healthy weight protects the result. Our rehabilitation guide describes what a recovery plan can look like.