Flat foot is also known as ‘pes planus’. In this condition the normal arch of the foot collapses, so the sole of the foot comes into contact with the ground. This deformity is usually present in both feet.
In children, usually the feet look flat due to non-development of arch, and deposition of normal ‘baby fat’. Flat arches in children usually become proper arches and high arches while the child progresses through adolescence and into adulthood.
Flat feet can also develop in an adult (adult acquired flatfoot) due to injury, illness, unusual or prolonged stress to the foot, faulty bio-mechanics, or as part of the normal ageing process. This is most common in women over 40 years of age.
Flat foot deformity can be easily diagnosed by examining the patient standing or just looking at them. On standing on tip toe,the deformity will correct itself when this is a flexible flat foot in a child with lax joints.
Such correction is not seen in the adult with a rigid flat foot. An easy and traditional home diagnosis is the ‘wet footprint’ test, performed by wetting the feet in water and then standing on a smooth, level surface such as smooth concrete or thin cardboard or heavy paper. The more the sole of the foot makes contact (leaves a footprint), the flatter the foot.
Most flexible flat feet are asymptomatic, and do not cause pain. In these cases, there is usually no cause for concern, and the condition may be considered a normal human variant. But, sometimes the flat feet can put a strain on muscles and ligaments (the tissue that links two bones together at a joint). This may cause pain in your legs on walking. Rigid flat foot often indicates a significant problem in the bones of the affected feet, and can cause pain in about a quarter of those affected.
Some people with flat feet find that their weight is distributed unevenly, particularly if their foot over-pronates. If the foot over-pronates, it is likely that the shoes will wear out quickly. Over-pronation can also damage the ankle joint and Achilles tendon. It is not fully understood what causes the tendon to become stretched, but some experts believe that wearing high heels and standing or walking for long periods may play a part.
Treatment is not usually needed for flat feet because they do not usually cause any significant problems. It may be required if there is associated foot or lower leg pain, or if the condition affects the knees or the lower back. Treatment may include using orthoses such as an arch support, or foot exercises. The pain is usually relieved by wearing supportive shoes that fit properly. It may be needed to wear shoes that are wider than normal.
In cases of severe flat foot, orthoses should be used through a gradual process to lessen discomfort. Over several weeks, slightly more material is added to the orthoses to raise the arch. These small changes allow the foot structure to adjust gradually, as well as giving the patient time to acclimatise to the sensation of wearing orthoses. Once prescribed, orthoses are generally worn for the rest of the patient’s life.
In some cases, surgery can provide lasting relief, and even create an arch where none existed before; it should be considered a last resort, as it is usually very time consuming and costly. In rare cases, surgery may be needed where a child has flat feet due to a problem they are born with (a congenital abnormality). The foot may need to be straightened, or the bones may need to be separated if they are fused together.
Stretching your feet can help to relieve pain associated with flat feet. Put your hands on a wall in front of you and place one foot ahead of the other. Keep your heels flat and bend your front knee and hold the stretch for 15 seconds. Then bend your back knee, bringing the heel up and hold for 15 more seconds. If you do this five to 10 times daily with each foot your arches should hurt less during the day.