A fallen arch or flatfoot is known medically as pes planus. The foot loses the gently curving arch on the inner side of the sole, just in front of the heel. If this arch is flattened only when standing and returns when the foot is lifted off the ground, the condition is called flexible pes planus or flexible flatfoot. If the arch disappears in both foot positions -- standing and elevated -- the condition is called rigid pes planus or rigid flatfoot.
Flexible flatfeet are considered normal in young children because babies are not born with a normal arch. The arch may not form fully until sometime between ages 7 and 10. Even in adulthood, 15% to 25% of people have flexible flatfeet. Most of these people never develop symptoms. In many adults who have had flexible flatfeet since childhood, the missing arch is an inherited condition related to a general looseness of ligaments. These people usually have extremely flexible, very mobile joints throughout the body, not only in the feet. Flatfeet also can develop during adulthood. Causes include joint disease, such as rheumatoid arthritis, and disorders of nerve function (neuropathy).
Unlike a flexible flatfoot, a rigid flatfoot is often the result of a significant problem affecting the structure or alignment of the bones that make up the foot's arch. Some common causes of rigid flatfeet include:
The majority of children and adults with flexible flatfeet never have symptoms. However, their toes may tend to point outward as they walk, a condition called out-toeing. A person who develops symptoms usually complains of tired, aching feet, especially after prolonged standing or walking.
Symptoms of rigid flatfoot vary depending on the cause of the foot problem:
If your child has flatfeet, his or her doctor will ask about any family history of flatfeet or inherited foot problems. In a person of any age, the doctor will ask about occupational and recreational activities, previous foot trauma or foot surgery and the type of shoes worn.
The doctor will examine your shoes to check for signs of excessive wear. Worn shoes often provide valuable clues to gait problems and poor bone alignment. The doctor will ask you to walk barefoot to evaluate the arches of the feet, to check for out-toeing and to look for other signs of poor foot mechanics.
The doctor will examine your feet for foot flexibility and range of motion and feel for any tenderness or bony abnormalities. Depending on the results of this physical examination, foot X-rays may be recommended.
X-rays are always performed in a young child with rigid flatfeet and in an adult with acquired flatfeet due to trauma.
Although infants are usually born with flexible flatfeet, most develop normal arches sometime between ages 7 and 10. In the 15% to 20% of children whose flatfeet last into adulthood, the condition often is inherited and lifelong. However, it may not cause symptoms.
A rigid flatfoot is a long-term condition, unless it is corrected with surgery or other therapy.
Because most cases of flatfeet are inherited, the condition is usually impossible to prevent. Even when children with flexible flatfeet are treated with arch supports and corrective shoes, there is little evidence that these devices prevent the condition from lasting into adulthood.
For mild pain or aching, acetaminophen (Tylenol) or a nonsteroidal anti-inflammatory drug (NSAID), such as aspirin or ibuprofen (Advil, Motrin and others) may be effective.
When there are no symptoms, treatment is not needed.
If a child older than age 3 develops symptoms, the doctor may prescribe a therapeutic shoe insert made from a mold of the child's foot or a corrective shoe. As an alternative, some doctors recommend store-bought arch supports. These appear to work as well as more expensive treatments in many children. With any conservative, nonsurgical treatment, the goal is to relieve pain by supporting the arch and correcting any imbalance in the mechanics of the foot.
Surgery is typically offered as a last resort in people with significant pain that is resistant to other therapies.
The treatment of a rigid flatfoot depends on its cause:
Call your doctor for persistent or unexplained foot pain, whether or not you have flatfeet. This is particularly important if your foot pain makes it difficult for you to walk.
Call your pediatrician or family doctor if your child complains about foot pain or appears to be walking abnormally. Even if there are no foot symptoms, it is wise to check with your doctor periodically about your child's foot development just to be sure that everything is progressing as expected.
Up to 20% of children with flexible flatfeet remain flatfooted as adults. However, most do not have any symptoms. If a child with flexible flatfeet begins to have foot pain, conservative treatment with shoe modifications can usually relieve the discomfort, although it may not correct the problem permanently.
For rigid flatfeet, the outlook depends on the cause of the problem:
National Institute of Arthritis and Musculoskeletal and Skin Diseases
National Insitutes of Health
1 AMS Circle
Bethesda, MD 20892-3675
American Podiatric Medical Association (APMA)
9312 Old Georgetown Road
Bethesda, MD 20814
American Academy of Podiatric Sports Medicine
American College of Foot and Ankle Orthopedics and Medicine
5272 River Road, Suite 630
Bethesda, MD 20816
American College of Foot and Ankle Surgeons
8725 West Higgins Road
Chicago, IL 60031-2724