The Mystique and Truths of Flat Feet

Wen Shen, MD

Orthopedic Associates of Dutchess County, PC

Flat feet seem to get a bad rap. It is a common problem I hear about almost every day. Not all flat feet are bad. The bottom line is that if it doesn’t hurt – if it ain’t broke – don’t fix it. If a middle aged adult has had flat foot arches all of his or her life and it hasn’t hurt and the shape hasn’t changed since the teenage years, chances are it will continue to function pain-free for many more years to come. However, the fear is that one day their flat feet will become painful. The myth is that this is inevitable. The truth is that it is not. But there are a few things to know.

Children are born with flat feet. During the first couple of years of life, baby fat obscures any arch and most toddlers can’t stand still long enough for you to notice anyway. Through the early childhood years, flat feet are very common and generally assume their eventual adult shape by early adolescence. Any change in the arch in adulthood, especially if it occurs only on one side but not the other, is abnormal.

Flat feet are generally categorized as painful or painless, flexible or rigid. A simple test of flat foot flexibility is the tip toe test. This is a good test for persons of all ages. Tip toeing consistently recreates an arch even though that person may have a very flat arch when standing still. If the tip toeing is easy and not painful and arch forms completely, then chances are there will be no problem. However, decreased flexibility in other areas, for example, a tight Achilles tendon or hamstring muscles, can eventually be a source of problems despite having flexible flat feet. If an arch does not form (best viewed from behind) or tip-toeing is very difficult, then there is a problem. Usual reasons for this are pain, weakness, and/or a rigid flat foot. A painless rigid flat foot has a higher risk of eventually becoming painful and an evaluation by a health care professional may be necessary to try to minimize that risk. Inability to tip toe because of pain or weakness would result in decreased walking endurance and professional evaluation is necessary.

Painful flat feet in children are rare and should be evaluated by a health care professional who specializes in foot problems. The typical flat foot in a child is painless and flexible. Maintaining flexibility in the leg joints and muscles, especially the hamstring muscles and Achilles, generally will ensure that the foot will remain painless. (Don’t skip those stretching exercises in gym class!) Flat feet in adults come in several different types, but in general, if it is flexible, has not changed shape, and is painless, there is probably no need to do anything.

The bewildering variation of orthoses (commonly called “arch supports” or “shoes inserts”) on the market contribute to the mystique of flat feet. Orthoses have a controversial role in the painless flat foot. They have not been shown to alter the natural history of arch development; that is, an arch that is flat now can remain flat even after years of orthoses use. A 5-year-old child with flat feet can wear orthoses for 10 years and have normal arches at age 15, but so can a similar child who does not wear orthoses during those years. Orthoses do however, have a proper role in the treatment of many types of painful foot conditions, including a painful flat foot. Because of the many types available, one often needs help choosing the appropriate type. Even for people who do not need a custom fitting can benefit from advice from an orthopedic surgeon, podiatrist, or orthotist.

One of the most common causes of painful adult flat foot is posterior tibial tendon dysfunction (PTTD). The posterior tibial tendon is the main tendon and muscle unit that supports the arch (it is not the only thing to support the arch, though). It usually causes pain related to activities referred to the inside (“medial” side) of the ankle or arch area. The source is usually wear and tear in the tendon from age, excessive weight, or both. Occasionally, a person may recall an injury that started the symptoms. In the early stages, the arch is normal and one may only notice discomfort or swelling in this area and may consciously or subconsciously limit his or her activities to avoid the pain. As the tendon continues to deteriorate, the arch collapses and pain becomes more prevalent. Paradoxically, if the tendon tears completely, pain may suddenly improve for a short period. As PTTD progresses however, the flat foot eventually becomes inflexible and pain may spread to other areas of the foot or ankle.
 

Treatment of PTTD typically starts with attempts to stop the inflammation of the posterior tibial tendon. This would consist of anti-inflammatory medications, such as ibuprofen, and various methods of short-term or long-term bracing which would relieve strain on the tendon. If this is successful, well-fitted orthoses and strengthening exercises can maintain good function with minimal discomfort. However, if short-term bracing and medications are not successful, surgery may be necessary to correct the problem. The exact surgical procedure would be individualized to a patient’s degree of deformity and dysfunction. It could consist of any number of methods to repair or reconstruct the posterior tibial tendon. Frequently some alteration of the bony architecture is necessary to gain a better mechanical advantage for the new tendon to avoid a recurrence of the PTTD. Joint fusions are used in the most severe cases.

Other less common causes of painful adult flat foot are arthritis and traumatic injuries. Diabetics and individuals with nerve damage to the feet are at risk of developing a type of painless rigid flat foot because of changes to the bone. While this last type of flat foot will probably never cause pain, it is a dangerous type because it can lead to skin problems and infections; therefore, a professional evaluation is necessary.

Dr. Shen is a Board-certified orthopedic surgeon with fellowship training in foot and ankle surgery.