What Is It?

A fallen arch or flatfoot is known medically as pes planus. The foot loses the gently curving arch that normally is on the inner side of the sole, just in front of the heel. If this arch is lost only during standing, and the arch returns when the foot is elevated off the ground, the condition is called flexible pes planus or flexible flatfoot. If the arch is lost in both foot positions — standing and elevated — the condition is called rigid pes planus or rigid flatfoot.

Flexible Flatfoot Or Flexible Pes Planus
Flexible flatfeet are considered to be a normal condition in young children. This is because the normal foot arch is not present at birth, and it may not form fully until sometime between ages 7 and 10. Even in adulthood, 15 percent to 25 percent of people have flexible flatfeet, and most of these people never develop symptoms. In many adults who have had flexible flatfeet since childhood, the absent 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).

Rigid Flatfoot Or Rigid Pes Planus
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 for rigid flatfeet include:

• Congenital vertical talus — In this condition, the arch is eliminated because the foot bones are not aligned properly. In some cases, there is a reverse curve (rocker-bottom foot) in place of the normal arch. Congenital vertical talus is a rare condition that is present at birth and often is associated with a genetic disorder, such as Down syndrome, or other congenital disorders. Up to half have no known cause.



• Tarsal coalition (peroneal spastic flatfoot) — This is an inherited condition in which two or more of the foot bones are fused together, interfering with the flexibility of the foot and eliminating the normal arch. It is a rare condition that often affects several generations of the same family.



• Lateral subtalar dislocation — This sometimes is called an acquired flatfoot, because it occurs in someone who originally had a normal foot arch. In a lateral subtalar dislocation, there is a dislocation of the talus bone, an important bone located within the arch of the foot. The dislocated talus bone slips out of place, drops downward and sideways, and collapses the arch. It usually occurs suddenly because of a high-impact injury related to a fall from a height, a motor vehicle accident or participation in sports, and it may be associated with fractures or other injuries.

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:

• Congenital vertical talus — The foot of a newborn with congenital vertical talus typically has a convex “rocker-bottom” shape, like the bottom rails of a rocking chair, sometimes together with an actual fold at the midfoot. The rare patient who is diagnosed at an older age often has a “peg-leg” gait, poor balance and heavy calluses on the soles where the arch would normally be. If a child with congenital vertical talus has an underlying genetic disorder, additional symptoms often are seen in other parts of the body besides the feet.



• Tarsal coalition — Many patients have no symptoms, and the condition is discovered only by chance when an X-ray of the foot is obtained for some other problem. When symptoms occur, there is usually foot pain that begins at the outside rear of the foot, then spreads upward to the outer ankle and outside portion of the lower leg. Symptoms usually start during a child’s teen-age years and are aggravated by playing sports or walking on uneven ground. In some cases, the condition is discovered when the child is evaluated for unusually frequent ankle sprains.



• Lateral subtalar dislocation — Because this often is caused by a traumatic, high-impact injury, the foot may be significantly swollen and deformed. There also may be an open wound with bruising and bleeding.

If your child has a flatfoot, his or her health-care provider will ask about any family history of flatfeet or inherited foot problems. In a patient of any age, the doctor will ask about occupation and recreational activities, previous foot trauma or foot surgery, and the type of shoes worn.

Then the doctor will examine the patient’s shoes to check for signs of excessive wear. Worn shoes often can provide valuable clues to gait problems and poor bone alignment. Next, the doctor will ask the patient to walk barefooted to evaluate the arch area of the feet, to check for out-toeing, and to look for other signs of poor foot mechanics.

Finally, the doctor will examine the feet to evaluate foot flexibility and range of motion, and to 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 done in a young child with rigid flatfeet, and in an adult with acquired flatfeet due to trauma.

Although infants usually are born with flexible flatfeet, most develop normal arches sometime between the ages of 7 and 10. In the 15 percent to 20 percent of children whose flatfeet persist 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.

Since most cases of flatfeet are inherited, the condition is hard to prevent. Even when children with flexible flatfeet are treated with arch supports and corrective shoes, there is little evidence that this prevents the condition from persisting into adulthood.

For any 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.

Flexible Flatfoot
When there are no symptoms, treatment is not needed.

If a child develops symptoms and is older than age 3, the doctor may prescribe a custom-made therapeutic shoe insert made from a mold of the child’s foot, called an orthosis, or a corrective shoe. As an alternative, some doctors recommend store-bought arch supports, since these appear to work as well as the more expensive treatments in many individuals. In all of these conservative, nonsurgical treatments, the goal is to relieve pain by supporting the arch and correcting any imbalance in foot mechanics.

Surgery typically is offered as a last resort in patients with significant pain that is resistant to other therapies.

Rigid Flatfoot
The treatment of a rigid flatfoot depends on its cause:

• Congenital vertical talus — At first, some doctors try a period of a procedure called serial casting. In this process, the foot is placed in a cast and the cast is changed frequently to reposition the foot gradually, but this generally has a low success rate. Most patients ultimately need surgery to correct the problem.



• Tarsal coalition — Treatment depends on the age of the patient, extent of bone fusion and severity of symptoms. For milder cases, your doctor may recommend conservative nonsurgical treatment with shoe inserts, strapping or temporary immobilization in a cast. For more severe cases, surgery is necessary to relieve pain and improve the flexibility of the foot.



• Lateral subtalar dislocation — The goal of treatment is to move the dislocated bone back into place as soon as possible. If there is no open wound, the doctor may be able to perform a procedure called a closed reduction under general anesthesia or spinal anesthesia. In this procedure, the doctor pushes the bones back into proper alignment without making an incision. Once this is accomplished, a short-leg cast must be worn for about four weeks to help stabilize the joint permanently. About 15 percent to 20 percent of patients with lateral subtalar dislocation must be treated with an open reduction, in which surgery is used to reposition the dislocated bone.

Call your doctor whenever you have 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 if you are concerned that your child may 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 percent 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 foot arch permanently.

For rigid flatfeet, the prognosis depends on the cause of the problem:

• Congenital vertical talus — Although surgery usually can correct the poor alignment of foot bones, many children with congenital vertical talus have underlying disorders that cause muscle weakness or other problems that interfere with full recovery.



• Tarsal coalition — When shoe modifications and orthoses are not effective, casting can help many patients to improve. When surgery is necessary, the prognosis depends on many factors, including which bones are fused, the specific type of surgery and whether or not there is any arthritis in the foot joints.



• Subtalar dislocation — With proper treatment, most patients recover without severe long-term complications or disability. In some cases, there is continuing stiffness in the area of the foot arch, but this does not necessarily cause pain or difficulty in walking. The risk of long-term problems is lowest in people who have at least three weeks of aggressive physical therapy after their casts are removed.

Diseases and Conditions Center

All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.