
Flat feet can develop as an adult ("adult acquired flatfoot") due to injury, illness, unusual or prolonged stress to the foot, faulty biomechanics,[5] or as part of the normal aging process. Flat feet can also occur in pregnant women as a result of temporary changes, due to increased elastin (elasticity) during pregnancy. However, if developed by adulthood, flat feet generally remain flat permanently.
Causes
There are a number of different causes that can lead to flat feet or fallen arches. These include, birth defects, while technically not a defect as such, flat feet can be a normal finding in patients from birth. However, a condition called tarsal coalition may occur where some of the bones in the foot are fused together resulting in a flatfoot. Inflammation or damage of the posterior tibial tendon. This tendon forms the end of a muscle that connects the lower leg to the foot, winding around the ankle and attaching to the inner aspect where the arch is normally present. The main role of the posterior tibial tendon is to invert the foot and maintain the arch height throughout the gait cycle. Torn muscles of the leg and foot can cause flat feet. Problems with the nerve supply to the muscles can result in reduction in tone and fallen arches. Fracture dislocation of the bones in the foot. Severe arthritis. While these are the common causes that can result in fallen arches and flat feet, it is important to recognise that there are certain risk factors that can also lead to this condition. These include advancing age, diabetes mellitus, high blood pressure, obesity and pregnancy.
Symptoms
Flat feet may not cause any symptoms at all. Rigid flat feet may cause pain, calluses, blisters, or skin redness on the inner side of the foot. A stiff foot, weakness or numbness of the foot, Rapid wearing out of shoes-worn shoes lean in toward each other. Difficulty or pain with activities like running-in the foot, knee or hip.
Diagnosis
Most children and adults with flatfeet do not need to see a physician for diagnosis or treatment. However, it is a good idea to see a doctor if the feet tire easily or are painful after standing, it is difficult to move the foot around or stand on the toes, the foot aches, especially in the heel or arch, and there is swelling on the inner side of the foot, the pain interferes with activity or the person has been diagnosed with rheumatoid arthritis. Most flatfeet are diagnosed during physical examination. During the exam, the foot may be wetted and the patient asked to stand on a piece of paper. An outline of the entire foot will indicate a flattened arch. Also, when looking at the feet from behind, the ankle and heel may appear to lean inward (pronation). The patient may be asked to walk so the doctor can see how much the arch flattens during walking. The doctor may also examine the patient's shoes for signs of uneven wear, ask questions about a family history of flatfeet, and inquire about known neurological or muscular diseases. Imaging tests may be used to help in the diagnosis. If there is pain or the arch does not appear when the foot is flexed, x-rays are taken to determine the cause. If tarsal coalition is suspected, computed tomography (CT scan) may be performed, and if an injury to the tendons is suspected, magnetic resonance imaging (MRI scan) may be performed.
What does it mean when you have flat feet?
Non Surgical Treatment
If you have fallen arches, but you are not experiencing any symptoms, then you probably do not need to seek treatment. If you are experiencing discomfort due to fallen arches, there are several treatment options. These treatment options include elevating the feet and applying ice to ease discomfort and reduce swelling, rest, exercises to stretch the feet, physical therapy, medication, such as anti-inflammatories, steroid injections and orthotic devices or customised arch supportsto wear in the shoes. If you have fallen arches and periodically experience pain related to that condition, it is a good idea to get orthotic devicesor custom arch supports, to wear in your shoes. The other treatment options, like medication and ice, will help to ease pain from fallen arches after you have already begun to experience pain. However, orthotic devices or(custom arch supports)can help to prevent pain from occurring at all. This preventative measure helps many people with fallen arches to avoid pain and prevent worsening of their condition. In severe cases of fallen arches, surgery may be required to correct the problem. You can also help to prevent pain and exacerbation of fallen arches by reducing your risk factors. If you are overweight, try to lose weight. Even a small weight loss can reduce the pressure on your feet significantly. If you are diabetic, manage your blood sugar as best as possible. Losing weight often also improves the condition of diabetics. You should also avoid high-impact activities, like running on the road, tennis, and sports that involve jumping. Try a gentler form of exercise, like swimming, instead. If you have fallen arches, orthotic devices or(custom arch supports)are an important component of your treatment and can help to prevent pain.
Surgical Treatment

This is rare and usually only offered if patients have significant abnormalities in their bones or muscles. Treatments include joint fusion, reshaping the bones in the foot, and occasionally moving around tendons in the foot to help balance out the stresses (called tendon transfer).
Prevention
Wear Supportive Footwear. Spend the money it takes to get proper fitting and quality footwear with good arch supports. Most sufferers of fallen arches and plantar fasciitis are born with high arches that sag as they get older. Good footwear can prevent this from becoming a problem. Flat feet, however, can become just as problematic. So, really we should all be wearing good footwear to avoid this potentially painful condition. Take It Easy. If your heel starts to hurt, take a rest. If the pain doesn?t go away after several days of resting, it may be time to see a podiatrist. Orthotics. Special insoles to support the arch of the foot can provide some much needed help. You can buy these at your local drugstore (not recommended), or you can have them specially made and custom fit for your feet. It can take awhile to get just the right one for your foot, but sometimes it can be just what you needed. Weight Control. Yes, maintaining a sensible diet with your ideal weight can be beneficial in many ways. It makes sense to think that the more weight your arches are supporting, the more easily they will fall and become painful.