Flat feet can develop as an adult ("adult acquired flatfoot") due to injury, illness, unusual or prolonged stress to the foot, faulty biomechanics, 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.
The arches of most individuals are fully developed by the age of 12 to 13. While some people are born with flat arches, for others, the arches fall over time. The tibial tendon, which runs along the inside of the ankle from above the ankle to the arch, can weaken with age and with heavy activity. The posterior tendon, main support structure for the arch, can become inflamed (tendonitis) or even tear if overloaded. For women, wearing high heels can affect the Achilles tendon and alter the structure and function of the ankle. The posterior tibial tendon may compensate for this stress and break down, causing the arches to fall. Obesity is another contributing factor, as well as a serious injury to the ankle or foot, arthritis and bad circulation such as occurs with diabetes.
A significant number of people with fallen arches (flat feet) experience no pain and have no problems. Some, however, may experience pain in their feet, especially when the connecting ligaments and muscles are strained. The leg joints may also be affected, resulting in pain. If the ankles turn inwards because of flat feet the most likely affected areas will be the feet, ankles and knees. Some people have flat feet because of a developmental fault during childhood, while others may find that the problem develops as they age, or after a pregnancy. There are some simple devices which may prevent the complications of flat feet.
Your doctor will ask about your symptoms and medical history. A physical and foot exam will be done. Flat feet can be diagnosed by appearance. To determine if the foot is rigid, you may be asked to do some simple tasks.
Non Surgical Treatment
Physiotherapists will carry out a detailed biomechanical assessment of your feet and lower limb. Once the causes have been identified a number of treatment methods may be used to help relieve pain and restore function in the feet including the use of custom made orthotics to support the foot and offload the areas which are painful, strengthening exercises for weakened muscles and tendons in the arch, and massage and mobilisation techniques to help mobilise stiff tissue and joints in the foot.
Surgical correction is dependent on the severity of symptoms and the stage of deformity. The goals of surgery are to create a more functional and stable foot. There are multiple procedures available to the surgeon and it may take several to correct a flatfoot deformity. Stage one deformities usually respond to conservative or non-surgical therapy such as anti-inflammatory medication, casting, functional orthotics or a foot ankle orthosis called a Richie Brace. If these modalities are unsuccessful surgery is warranted. Usually surgical treatment begins with removal of inflammatory tissue and repair of the posterior tibial tendon. A tendon transfer is performed if the posterior tibial muscle is weak or the tendon is badly damaged. The most commonly used tendon is the flexor digitorum longus tendon. This tendon flexes or moves the lesser toes downward. The flexor digitorum longus tendon is utilized due to its close proximity to the posterior tibial tendon and because there are minimal side effects with its loss. The remainder of the tendon is sutured to the flexor hallucis longus tendon that flexes the big toe so that little function is loss. Stage two deformities are less responsive to conservative therapies that can be effective in mild deformities. Bone procedures are necessary at this stage in order to recreate the arch and stabilize the foot. These procedures include isolated fusion procedures, bone grafts, and/or the repositioning of bones through cuts called osteotomies. The realigned bones are generally held in place with screws, pins, plates, or staples while the bone heals. A tendon transfer may or may not be utilized depending on the condition of the posterior tibial tendon. Stage three deformities are better treated with surgical correction, in healthy patients. Patients that are unable to tolerate surgery or the prolonged healing period are better served with either arch supports known as orthotics or bracing such as the Richie Brace. Surgical correction at this stage usually requires fusion procedures such as a triple or double arthrodesis. This involves fusing the two or three major bones in the back of the foot together with screws or pins. The most common joints fused together are the subtalar joint, talonavicular joint, and the calcaneocuboid joint. By fusing the bones together the surgeon is able to correct structural deformity and alleviate arthritic pain. Tendon transfer procedures are usually not beneficial at this stage. Stage four deformities are treated similarly but with the addition of fusing the ankle joint.