Flat feet (pes planus) is a term used to describe a common structural condition where the feet have no arch. If you have flat feet, the entire sole of the foot touches the floor when you stand. Flat foot is not necessarily a painful condition, although it can cause problems elsewhere in the lower limbs due to structures being pushed out of alignment. Flat feet can lead to conditions such as tendonitis, arthritis, bunions, hammertoes, shin splints and plantar fasciitis.
The arch of the foot develops during childhood, so babies and toddlers have naturally flat feet that gradually develop arches. Some people never develop them. Others do, but age can cause the weakening of the posterior tibial tendon that runs from the tibia (shinbone), under the inner anklebone and into the long metatarsal bones of the foot. This tendon helps to support the arch, so if loose the arch may collapse.
Obesity can be another cause of flat feet. Excessive weight on the tendon will stretch or damage it. Weight gain and hormonal changes during pregnancy can also weaken the tendon.
Injury to the foot or ankle might cause the arch to collapse, and rheumatoid arthritis can progressively destroy tendon tissues.
The Achilles tendon runs from the posterior calf muscles down to the heel bone and is visible as a cord at the back of the ankle. People with a short Achilles tendon may have flat feet.
Rarely, flat feet in children are caused by tarsal coalition, a painful condition where two or more bones in the foot fuse together.
Flat feet may or may not be symptomatic. If no discomfort is being experienced, no treatment is necessary. If symptoms are present, they may include:
- Aching pain in the foot, especially in the arch or heel area, worse after standing for extended periods or playing sports
- Swelling on the inside of the ankle, along the path of the posterior tibial tendon
- Pain experienced in the calf, knee, hip or lower back
- Stiffness in one or both feet
An easy home test for flat feet is to wet your foot and stand on a surface that will show an imprint, such as construction paper, or a sidewalk. Flat feet will leave a complete impression of your foot (as opposed to there being a space where your arch did not touch the ground).
Your doctor will physically examine your foot. You will probably be asked to stand and walk so that your doctor can evaluate the extent and severity of the condition, and see how weight is being distributed across the foot. You may be asked to stand on tiptoe so that your doctor can see if an arch forms when you do so. If it does, the flat foot is termed ‘flexible’ and no treatment is required. If no arch forms, the foot is called a ‘caled rigid flat foot’.
X-rays may be taken if your doctor needs to have a closer look at the bone structure of your feet. CT (computer tomography) or MRI (magnetic resonance imaging) scans may also be required to view the bones and soft tissues in the feet.
Treatment is only necessary if flat feet are causing problems. A child with flat feet but no painful symptoms will continue to develop the same, regardless of any orthotics used. He or she will not make flat feet worse by leading a normal, active life.
Tarsal coalition is treated primarily with rest, and sometimes a cast to restrict movement of the foot. If this fails to resolve the problem, surgery might be needed to repair the tendon or fuse some joints in the foot.
For adults, the main treatment for flexible flat feet that are causing pain is the wearing of orthotic insoles or wedges. You can try readily available arch supports, or you may need to have custom orthotics made. Custom orthotics are specially molded to the exact contours of your feet. Although they will not cure flat feet, they can help alleviate painful symptoms by lifting the arch and redistributing weight across the foot.
Exercises to stretch the Achilles tendon will help those whose flat feet are caused by a short tendon. Other exercises to stretch and strengthen the foot may help to relieve symptoms.
Occasionally surgery is necessary to repair a badly torn posterior tibial tendon that has caused the arch to collapse with subsequent severe pain.
You can help to reduce pain by resting the feet and avoiding activities that make the symptoms worse. Over-the-counter pain medication such as acetaminophen or ibuprofen can be taken as directed.
Losing weight if you are overweight will reduce the stress placed on the arches and provide some relief from pain.
Exercises to stretch the tendons in the foot and ankle, and to strengthen the supporting muscles, should be done regularly. Be sure to exercise each foot equally in order to avoid developing an imbalance between them, and always do these exercises barefoot.
Simply spending as much time as possible barefoot, or in socks, will encourage the foot to use its muscles. Walking barefoot in sand is an extremely effective way to strengthen your feet.
Stand facing a wall and place hands on it for support. Lean forwards until a stretch is felt in the calves. Hold for 30 seconds. Bend at knees and hold for a further 30 seconds. Repeat 5 times.
Achilles tendon stretch:
Stand with your toes on the edge of a step and your heels over the edge. Have a support such as a wall next to you. Slowly raise your heels as high as you can, then lower your heels to their lowest point. Do this slowly and steadily in order to avoid damaging the tendon. Repeat 20 times.
Sitting, standing or lying down, fan out your toes as far as they will go, creating as much space between them as possible. Hold the spread for 10 seconds. Repeat 10 times.
Point your toes at an object, then flex the foot and hold for 5 seconds. Repeat 10 times.
Walk around on your toes, gradually building up to 5 minutes per day, without letting your heels touch the ground.
Place your feet shoulder width apart. Slightly bend your knees and roll the feet out so you are standing on the outer edges. Keep the weight on the outside of your feet and slowly rise up onto your toes. When you feel a stretch in the arch, hold the position for 5 seconds. Repeat this exercise 5 times a day.