Flat foot

Marian Grosser studied human medicine in Munich. In addition, the doctor, who was interested in many things, dared to make some exciting detours: studying philosophy and art history, working on the radio and, finally, also for a Netdoctor.

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Flatfoot (pes planus) is a foot malposition in which the natural longitudinal arch of the foot skeleton (arch of the foot) is missing. Flatfoot is when the entire sole of the foot is in contact with the ground while standing. Flat feet can be congenital or develop in the course of life. Depending on the severity, the flat foot can cause pain and restrict movement. Read all about flat feet and how to treat them.

ICD codes for this disease: ICD codes are internationally recognized codes for medical diagnoses. They can be found, for example, in doctor's letters or on certificates of incapacity for work. M21Q66

Flatfoot: description

In contrast to a healthy foot, the skeleton of a flat foot does not have a longitudinal arch. So it lacks the natural outward curvature from the heel to the ball of the foot. As a result, the inner edge of the foot sinks so that the entire sole of the foot rests “flat” on the floor when standing.

In the case of a flat foot, however, it is not only the longitudinal arch that usually disappears. Depending on the shape and form, there are also other deformities of the foot skeleton. For example, the outer edge of the foot is raised (pronation). The Achilles tendon can be shortened and the heel and forefoot often bend to the outside (valgization or abduction). In such cases, doctors therefore also speak of a flat tire.

A preliminary stage of flat feet is the flat feet. With this shape, too, the skeleton of the foot loses its longitudinal curvature, but the sole of the foot is not yet fully on the ground.

What types of flat feet are there?

Flatfoot can exist from birth or it can be acquired, i.e. it can only appear later in life. The congenital form differs significantly from the acquired types, especially with regard to their frequency, origin and treatment.

Congenital flat feet (Pes planus congenitus)

Congenital flat feet are rare and often occur together with other malformations or diseases. One foot alone or both can be affected. The affected babies have a very pronounced deformity on the foot. Not only does it lose its natural longitudinal curvature, but the sole is even arched downwards.

The reason for this type of flat foot is that certain tarsal bones are in the wrong position. The talus, which connects the foot to the leg, is too steep and is also shifted towards the inside and sole of the foot. Thus, the talus cannot form normal articulations with other tarsal bones. Doctors also refer to the steep position of the ankle bone as the "vertical talus".

Acquired flat feet (Pes planus valgus)

Patients with acquired flat feet are initially born with a healthy foot skeleton and only later develop the deformity. Depending on the age at which it occurs, different types of acquired flat feet can be distinguished:

• Acquired, childlike flat foot: It occurs around the beginning of the running age.
• Adolescent flatfoot: develops in adolescence.
• Adult flat feet: can also only appear in later life.

The acquired flat foot in a child should not be confused with the natural (physiological) flat foot in childhood: children up to about the age of six have a different leg position than adults. Because their thigh bones are aligned differently, they walk slightly knock-knees, which also affects the position of the feet. A temporary arched arches is the result.

The strong longitudinal arch does not form until between the ages of six and ten, when the position of the legs also normalizes. The acquired, child's flat foot, on the other hand, has non-natural causes and remains permanent without treatment.

Flatfoot: symptoms

Whether a flat foot causes problems and, if so, how severe they are, depends largely on the cause and severity of the deformity. While congenital flatfoot usually causes increasing symptoms without therapy, mildly acquired forms can be completely symptom-free.

Symptoms of congenital flat feet

Congenital flat feet are noticed immediately after birth. The misalignments on the foot - such as the outwardly curved sole of the foot, the kinked heel and the outwardly splayed front section of the foot - are very pronounced here.

The affected children usually learn to walk later than their peers. Without timely treatment, however, movement is restricted, and from the later school age onwards, patients usually suffer increasingly from pain.

Symptoms of acquired flat feet

The acquired, childlike flat foot is usually symptom-free. The children only stand out because of the visible misalignment on their feet. Depending on the cause, movement can also be impaired.

Flat feet that occur in adolescence are usually accompanied by severe, sudden stress pain. The adolescents limp to protect the affected foot. Without treatment, adolescent flat feet can severely restrict movement.

Adults who develop flat feet often have symptoms there after more intense exertion. Above all, as long as the arch of the foot is still lowering, pain occurs. If the sole of the foot is completely on top, it often takes off again.

In the case of flat feet, the pain usually occurs on the inner edge of the foot and on the sole of the foot. The misalignment can also cause pain in the knees and even the hips. The heavy load on certain parts of the foot can also develop pressure points, which sometimes cause additional pain and make walking difficult. In many cases, however, those affected have no problems walking.

Flatfoot: causes and risk factors

Congenital flat feet seem to be mainly hereditary, as several members of the same family often have it. However, this does not mean that a child has to be born with flat feet if one of the parents was affected. Only the probability increases. The exact causes of congenital flat feet are not yet known.

There can be many triggers for acquired flat feet. The most common include:

• Long-lasting incorrect and overloading. Especially with young people this is often the reason for a flat foot ("apprentice flat foot")
• Connective tissue and muscle weakness. The acquired flat foot in a child is often due to muscle weakness.
• Joint inflammation (rheumatoid arthritis) often occurs in older people, but can also affect young people.
• Injuries after accidents or signs of wear and tear (osteoarthritis)
• Nerve diseases and paralysis
• the pathological growing together of several foot bones
• shoes that are too tight that do not allow the feet and toes to move freely

In older people, a pathologically altered tendon in the lower leg (tibialis posterior tendon) can also be the cause. If the tendon is heavily stressed for a lifetime, it can regress or tear and thus lead to a one-sided flat foot.

Flatfoot: examinations and diagnosis

To diagnose the acquired flat foot, the doctor checks to what extent the arch of the foot is still present. To do this, he looks at the feet when the patient is standing on the floor. Depending on how pronounced the flat foot is, the entire sole of the foot rests more or less heavily on the ground.

Another method is the footprint on an electronic measuring plate or a suitable modeling clay. The weight distribution of the sole of the foot can be clearly understood here.

If the flat foot cannot be clearly identified externally, an X-ray is taken. In the case of congenital flat feet, this is generally done as confirmation.

A torn tibialis posterior tendon, which is often the cause of a one-sided flat foot, can be recognized by the doctor by looking from behind at the feet on the floor. While only the heel can be seen on the healthy foot, the toes can also be seen on the injured foot. ("Too many toes sign").

Flat foot: treatment

There are several ways to treat flat feet. While acquired forms often do not require surgical intervention, surgery is usually unavoidable for congenital flat feet.

Therapy for congenital flat feet

First of all, the children are prepared for a later operation. To do this, you put a plaster of paris on the affected foot, which counteracts the deformity. However, this measure alone is not sufficient. Therefore, the children are usually operated up to the age of three to correct the incorrect position of the tarsal bones. This is followed by a follow-up treatment with special insoles and plaster casts, which can take months or even years. If there is still a misalignment after the foot has finished growing, a new intervention may be necessary.

Therapy for acquired flat feet

Physiotherapy exercises, which strengthen the muscles in the foot and lower leg, are particularly helpful in the early stages of acquired flat feet. Special orthopedic shoe insoles can also bring the foot back into shape. If the acquired flat foot causes severe pain, the doctor will prescribe medication.

If the symptoms do not improve as a result, an operation may also be necessary for acquired flat feet. In particular, flat feet caused by osteoarthritis or a torn tibialis posterior tendon are often operated on.

Flatfoot: disease course and prognosis

The congenital flat foot disrupts the child's walking development and mobility. However, the malalignment can usually be corrected with the help of an operation in good time.

With mild, acquired forms, those affected often have no symptoms. Should problems nevertheless arise, the acquired flat foot can usually be treated well with the help of a special shoe insert.

The risk of getting flat feet is reduced by avoiding excessive and one-sided loads on the feet. There is also a good and just as simple training for the feet: Those who regularly go barefoot train the muscles and ligaments of the foot and thus prevent an acquired flat foot.

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