Flat feet (pes planus) are extremely common. While usually just a normal anatomical variation that does not result in any serious difficulties, this condition, which causes the feet to lean inward, or pronate, can cause problems over time. Infants feet are naturally flat because of the pad of "baby fat" at the instep. As they grow and begin to walk, their feet normally develop arches. For some children this does not happen and their feet remain flatter than average. While this condition is usually inherited, there are many individuals who have normal arches as children and young adults, but develop flat feet, or "fallen arches," over time. These individuals are said to have acquired flat foot deformity (AFFD).
Risk Factors for Problematic Flat Feet
Apart from heredity, there are several risk factors that predispose certain individuals to developing flat feet that are troublesome and may require medical intervention. These risk factors include wear and tear due to aging or obesity, disease conditions such as rheumatoid arthritis, traumatic injuries, and dysfunctions of tendons or ligaments. The most serious of the latter is posterior tibial tendon dysfunction in which the primary tendon that supports the arch gradually becomes lax.
Types of Flat Feet
There are two basic types of flat feet: rigid and supple. If the medial longitudinal arch (MLA) is not visible whether the patient is either seated or standing, the condition is called rigid MLA. If, on the other hand, the MLA is present when the patient is seated or standing up on the toes, disappearing only when the patient stands, the condition is known as supple MLA. The latter condition is less serious and can most often be alleviated with the use of arch supports or orthotics.
Symptoms of Flat Feet
Many individuals with flat feet have no discomfort at all, but some may experience foot fatigue and pain. Some, particularly as they age, develop pain in the heel or arch area, or swelling along the inside of the ankle.
When the condition of an individual with flat feet deteriorates, the person may suffer from pain not only in the foot, but in the ankle, knee, or back. It is also common for such people to develop bunions, arthritis, or another foot or ankle deformity. In such cases, medical intervention may become necessary.
Diagnosis of Flat Feet
While flat feet are diagnosable through simple physical examination, diagnostic imaging tests may be used to detect anatomical abnormalities, soft tissue injuries, such as those affecting the tendons, and any arthritis that has developed in the area. Such imaging tests include:
- CT scan
- Ultrasound scan
- MRI scan
These tests are often necessary to determine whether treatment is necessary and, if so, what type.
Treatment of Flat Feet
For children with flat feet, walking barefoot, particularly on soft terrain like sand, is recommended. There is some evidence that this may assist them in developing normal arches. Wearing supportive shoes and orthotic devices can be helpful to individuals of any age.
Other treatments for pain or fatigue resulting from flat feet include over-the-counter anti-inflammatory medication, applications of ice packs, stretching exercises and physical therapy.
When flat feet have resulted in, or a have been caused by, more serious foot abnormalities, such as bone spurs or tendon ruptures, surgery may be required. Depending on the patient's condition, this may involve removing a bone spur, repairing a tendon or ligament, or fusing one or more bones of the foot.