Pés chatos e arcos caídos

What are flat feet?

Flat feet, or 'fallen arches', occur when the normal foot arches have partially or completely collapsed. When the foot is put to the ground the inner or middle side of the foot comes down to the floor rather than remaining raised.

This can cause the whole foot to roll inwards (this is called over-pronation). It is not considered a disorder if it doesn't cause any symptoms.

• Flat feet can be simply the way your feet are made, an abnormality present from birth. Flat feet can be inherited, just as we inherit other physical characteristics from our parents.

• Young children normally have flat feet. The arches of the feet only appear when standing when they get older (although in a child the arch can sometimes be seen when the child stands on tiptoe).

Conditions that cause flat feet

Isso inclui:

• Damaged, inflamed or torn tendons (particularly the posterior tibial tendon).

• Gradual stretch of the posterior tibial tendon (particularly common in women aged over 40. It is possible that wearing high heels for prolonged periods plays a part in this).

• Damage to the bones of the foot or ankle.

• Conditions affecting the joints and soft tissues, including artrite.

• Some conditions affecting the nerves such as paralisia cerebral, Doença de Parkinson e distrofia muscular, in which muscles become stiffer and weaker over time.

Other causes of flat feet

Flat feet are more likely to develop in people with:

• Obesidade - the additional weight will place added strain on the tendons which support the arches and they are more likely to collapse.

• Pressão alta - this may be an effect on the blood supply to the tendons in the foot.

• Diabetes - this affects the nerves in the feet and can also lead to weakness of the tendons.

• Pregnancy - a combination of added weight and the effects of pregnancy hormones which tend to soften supportive ligaments.

• Artrite reumatoide - this may weaken the tendons or affect the joints.

• A long history of running (straining the posterior tibial tendon).

• Greater age - the tendency of the tendons to tire and stretch increases with age.

• Larger feet. Those who have larger feet may be more prone to developing flat feet.

People who have had flat feet all their lives often typically have no symptoms at all. They are likely to have otherwise normal, flexible feet with no underlying tendon or joint problems, and their walking and running will have adapted to compensate. Between one in four and one in five adults have some degree of flat feet.

If flat feet do cause symptoms these may include:

• Foot pain:

  • This may be almost anywhere in the foot, depending on which part of the arch is dropping and which tendons are stretched or injured.

  • Pain may involve the whole foot or ankle, or just parts of it.

  • It is typically felt just inside the ankle, on the outer edge of the foot or in the arch itself.

  • The altered placement of the foot on the ground can then lead to pain in the calf, knee, thigh, hip or spine.

  • Over-pronation frequently leads to ankle pain and Tendinopatia de Aquiles.

• Foot stiffness.

• Uneven wearing of shoes.

• The sensation of foot flatness or imbalance (particularly if only one foot is affected).

• Your doctor or podiatrist can generally make this diagnosis just by observing your feet when you stand or walk.

• Footprint analysis (a pedograph) may be used.

• If the changes are recent a doctor will want to look for the underlying reason. This may involve testing your tendons and watching you walk; an raio-X or magnetic resonance imaging (ressonância magnética) scan of part or all of your foot may also be involved.

• You may suspect the diagnosis yourself by observing your wet footprint and noticing that the whole of the sole of your foot contacts the floor when you stand.

• If you push your big toe back as far as possible and the arch of your foot doesn't appear, your foot is likely to over-pronate when you walk or run.

In the past flat feet were a reason to be refused entry into the Armed forces. In fact, flat feet which do not cause symptoms do not need medical care.

• You should see a doctor to discuss your flat feet if:

  • The arches have dropped recently.

  • You are experiencing pain in your lower limbs.

  • Supportive, well-fitting shoes fail to help your aching feet.

  • Your feet feel stiff or heavy.

Depending on the symptoms:

• Foot pain may be alleviated by supportive, well-fitting footwear.

• Exercises may be helpful. This may involve, for example, toe curls and eccentric heel raises. An eccentric exercise is one where you exercise a muscle as it lengthens as opposed to as it shortens (contracts).

• Rest and ice can be useful, particularly after exercise.

• Physiotherapy can be useful to correct walking (gait) abnormalities which are developing because of the shape of the feet.

• Fitted insoles (arch supports designed for your foot) may relieve pressure on the arch. This may stop any tendency of the feet to roll inwards or outwards, which can otherwise increase lower limb and back pain.

• Wear shoes with low heels and wide toes.

• Walk barefoot when you can.

• Orthotic devices or ankle braces can be helpful if the posterior tibial ligament is inflamed. They may also be useful if the cause of the flat feet relates to problems with the nervous system or severe muscle weakness.

• Rest can be helpful, particularly if the problem has been made worse by overuse - for example, running on hard surfaces. Alternatively, consider switching to treadmill running for a time.

• Avoid high-impact sports which involve jumping and landing - for example, ballet and basketball.

• Perda de peso is likely to be helpful if you are at all overweight.

• Rarely, abnormalities of bones in the foot may be surgically treatable. Treatments may include fusing bones, removing pieces of bony growth (spurs), tendon enhancement surgery and bone grafting. These treatments are only considered in cases where pain or foot damage is severe and it is clear that surgery can approach the root cause of the problem.

The main complication is that, as flat feet become worse, the way you walk alters. This, together with loss of the ability of the feet to contribute as well to balance and spring, can increasingly lead to pain further up the legs and in the back.

This may include muscular pains, joint pains and inflammation of the tendons (for example, Tendinopatia de Aquiles e fascite plantar).

Altered walking and altered placement of the feet can also lead to further abnormalities of the feet such as joanetes, calluses, hammer toes and blisters.

The loss of impact absorption by the feet in athletes can mean that impact is transferred further up the leg. As a result, overuse injuries such as shin splints (tibial stress fractures) are more likely.

Most people are born with flat feet so they cannot be prevented. To avoid developing them when you are older it is sensible to avoid becoming overweight. If you wear high heels, you should avoid wearing them for prolonged periods of time.

The underside of a normal adult foot has an upward curve in the middle and this is called an arch. In fact there are two main arches, one running lengthways down the foot (longitudinal arch) and one running across the foot (transverse arch).

The arches are formed by the way in which the bones are held tightly together - particularly the bones of the midfoot. These bones are held firmly in place by tendons. Several tendons of the foot and lower leg are involved in forming the arches in this way.

These tendons attach the bones of the midfoot to the heel and they pull together to hold parts of the underside of the foot up off the ground. The most important tendon involved in the job is the posterior tibial tendon, which runs from the back of the leg behind the ankle bone then under the foot to the midfoot.

There is more information about the anatomy of the foot in the separate leaflet called Plantar Fasciitis (Heel and Foot Pain).

The feet are incredibly well designed, flexible structures made of 26 bones and over 100 muscles, tendons and ligaments. The three parts of the foot, anatomically, are:

• Forefoot: made up of the toes and the five long bones or metatarsals.

• Médio pé: um conjunto de ossos que formam os arcos do pé.

• Hindfoot: the heel and ankle.

Ligaments, tendons and muscles run alongside these bones, bonding them together and allowing the many movements the foot can make.

The arches of the feet help us to stand, balance, walk, run and jump. This is because they add springiness and flexibility to the foot by allowing the middle part of the foot to spread and close.

They help the foot to absorb the physical shock of landing and produce strength to push off and to adjust to balance and walk. They also help distribute the weight of the body evenly around the foot as we move.

Dr. Mary Lowth é autora ou a autora original deste folheto.