The first time can be describe as "Structural flat foot", a condition where the patient's foot is flat all the time--when lying down, sitting, standing, walking, running--whenever.

As you can see on the X-ray to the right, there is no significant arch noted in the foot.

This type of flat foot is completely caused by abnormal bone structure.

The second type of flat foot is what's known as a "Flexible Flat Foot". In this group you'd place feet that do have an arch when the patient is not bearing weight, but that arch disappears when the patient stands up. This is the type of flat foot that's associated with excessive pronation.

Pronation is a normal but complex motion of the foot that allows the foot to become a flexible adaptor to the ground. It can be desribed as the foot's shock absorption system.

(The motion opposite to pronation is supination, a motion that causes the arch to rise and allows the foot to become a rigid lever, to provide push off in gait.)

The problem occurs when the foot pronates more than it should. This condition goes by several different names (hyperpronation, pronated flat foot or "Flexible Flat Foot".

Each type of flat foot condition can occur in both adults and each can occur in children. As these conditions mean different things in each group, I will discuss each separately.

Actually, starting out, all babies have feet that look flat. This is because there is a great deal of fat at the bottom of the foot, (which makes the arch look flat), and because the arch is not properly formed until about age 3.

Thus, while it's important to have your child properly assessed by a podiatrist to discern whether the flat feet are normal or not, most cases of flat feet at this age turn out to be normal, and in general, need not be treated.

To the left is an example of a pathological pediatric flat foot.

If structurally flat feet persist beyond the age of 4 or 5, the child's feet should probably be examined by a doctor of podiatric medicine. Various structural problems, like improperly-developed or abnormally-joined bones, may be ruled out by x-ray or other tests. Your child simply having structurally flat feet doesn't mean he or she will need to be treated--but it is a good idea to rule out certain problems that can be best treated at younger ages.

The most obvious sign your child's feet should be examined, though, is if he or she complains of any pain in the foot or ankle. Often passed off as "growing pains", almost all such pains (which can be caused by a variety of problems) can be treated if the problem is carefully assessed and identified.

If the foot is simply structurally flatter than normal, but is without pain or functional abnormality, probably not.

If pain is present, or if the foot is a flexible flat foot, collapsing excessively in stance, then prescription functional Orthoses are more likely.

In the case with children, it is extremely important that the orthoses be properly designed and fabricated, so make certain you have a podiatrist examine your child's feet.

These devices can frequently be helpful for symptomatic relief of many types of problems. However, they do not adequately control a flexible flat foot--the kind of foot that severely collapses in stance. Having your child's feet thoroughly examined by a doctor of podiatric medicine is a good idea before you decide whether these devices will do more help or harm to the condition.

Some activities that require long-periods of ambulation and tend to lead to overuse can make symptoms worse, yes. We don't wish to limit your child's activities, however, so activities may need to be designed to diminish repetitive strain to uncomfortable tissues.

Surgery is not necessary for most patients with flat feet. But if your child's flat feet are caused by abnormally-fused foot bones, or if your child's flat feet are the type that collapse severely in stance, and if prescription functional orthoses are not helpful, surgery may be considered. Your podiatrist can help you make that decision.

Adults with flat feet almost never need to be treated unless there are symptoms somewhere. When symptoms are seen (which is, unfortunately common), symptoms are most commonly seen in the arches, ankle, lower leg, knee and lower back. Less common sites of discomfort associated with flat feet are the hip (seen more in women) and in the shoulder and neck areas. When pain associated with adult flat feet does occur, however, it is usually chronic.

When pain occurs in these regions, treatment is often necessary. Oral or injectible anti-inflammatory agents, massage, stretching, exercises, night-splints, immoblization, physiotherapy, massage, taping, padding, orthoses and shoe changes are common treatments.

Structurally flat feet and functionally flat feet tend to respond differently to the treatments mentioned above, however. When orthoses are designed, for example, each group tends to do better with a very specific type of device.

It is important, therefore, that adults with painful flat feet be seen by a podiatrist, specialists with a lot of experience in biomechanics (foot function), or you will likely find you've spent a lot of money to have devices that don't work well.