Flat feet

In people with flat feet, sometimes referred to as 'collapsed foot arch', the inside of the arch in both feet has collapsed. In severe cases, the arches are so collapsed that they even touch the ground, hence the term flat feet (pes planus).

How do flat feet develop?

In most cases, the cause of flat feet is congenital and therefore genetically determined. When one or both parents are born with flat feet, they can pass it on to their children. 

In non-congenital flat feet, there is often an underlying condition such as joint wear (osteoarthritis), rheumatoid arthritis or a local foot or ankle injury. Flat feet can also be caused by a nerve or muscle disease, for example after a stroke.

Pregnant women and people who are overweight or have diabetes have an increased risk of developing flat feet. Older adults are also more likely to develop them. With age, many muscles and tendons weaken, including the so-called tibialis muscle. This is an important supporter of the arch of the foot.

What are the symptoms of flat feet?

A hallmark of flat feet is the collapsed arch; as a result, the foot rolls inward when standing and walking. This is also called overpronation of the foot and can cause pain and fatigue in the feet during prolonged standing or walking. Long-standing, untreated flat feet can, due to the altered foot position, also cause symptoms in the ankle, knee, hip and even lower back.

How is the diagnosis of flat feet made?

In 'normal' feet, the distance from the ground to the inside of each arch is about 1.3 centimeters. In flat feet, this distance is smaller.

Flat feet are easy to establish during a physical examination, possibly supplemented with specific tests. The skin is also examined. The presence of calluses, thickenings and discolorations can provide more information about the changed position or use of the feet.

If necessary, an X-ray of the feet is taken. This can help visualize anatomical abnormalities that may play a role in the development of flat feet.

What is the treatment for flat feet?

Depending on the cause of the flat feet, several treatment options are possible. With a structural cause, such as a congenital foot deformity or a nerve or muscle disease, it may be necessary to support the collapsed arch using orthotic insoles. These can be fitted by a podiatrist. 

Other treatment options focus on reducing pain and tension on the arch. Losing weight in the case of overweight is a good first step. The physical therapist can provide excellent guidance with therapies such as mobilization techniques, taping and forms of exercise therapy.