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For many runners with painful foot problems, orthotics, which are prescription arch supports, offer salvation, enabling them to resume their activities; for others, though, they are only useful as expensive doorstops. This drastic disparity hinges on the accurate diagnosis of the problem and the subsequent proper selection of the orthotic that best addresses the problem. Orthotics are custom-made shoe inserts designed to improve foot function during gait. They work primarily by reducing excessive foot pronation -- the flattening of the arch and internal rotation of the leg that results in extra stress and strain on muscles, joints, tendons and nerves. The importance of this fact is revealed in studies that show runners who overpronate are injured more frequently. Orthotics make the foot function more efficiently, improving stability and shock absorption. Orthotics are fabricated by first taking a plaster impression of the foot (called a negative cast); this is done with the foot in a relatively nonweightbearing, or neutral, position. (Other techniques that require stepping down into a mold may result in a pronated cast and an orthotic that provides little correction.) The negative cast is then usually sent to an outside lab with the clinician's prescription (including the specific diagnosis, foot measurements, amount of desired correction and body weight). A positive cast is made that is an exact replica of the foot onto which the orthotic is constructed. Some labs may also incorporate computers into the process. Orthotic materials include graphite, polypropylene, leather, plastizote and PPT that can produce a rigid, controlling type of orthotic or a flexible, more accommodative one. Orthotics come in different shapes and lengths and can be made to fit into any type of shoe including high heels, sandals, bike shoes and running shoes. They usually require a two- to three week break-in period after which time the only thing noticeable should be the absence of symptoms. They should last for years, only needing to be replaced if the foot changes its shape or grows more than two shoe sizes. The main indications of custom foot orthoses are the prevention and conservative treatment of over-use type injuries: tendinitis, shin splints, plantar fasclitis/heel spur syndrome, metatarsalgia (forefoot pain), sesamoiditis and stress fractures, among others. They are used for structural problems such as limb-length discrepancies, flexible flat feet and intoeing in children. Since they improve lower extremity alignment, those with knee or lower back pain may even get relief. They serve a protective function in preventing bone fractures in people with diabetes or osteoporosis. Orthotics can also be helpful in delaying surgical treatment of bunions, harnmertoes or neuromas. Since almost no foot is perfect, one could make an argument to justify an orthotic for just about everyone of any age or activity level. On the other hand, "if it is not broken, it probably does not need fixing." Witness Zola Budd who ran quite successfully barefoot without problems. The rest of us, however, may have problems of varying degrees that are significantly alleviated by the use of orthotics. Why orthotics work for some people and not others is definitely subject
to debate. A recent study in the orthopedic literature found that an
inexpensive heel cushion was nearly as effective as a custom orthotic
for heel pain; this was refuted by a leading podiatrist who published
a more comprehensive retrospective study in which orthotic wearers reported
a 90% satisfaction rate for a variety of ailments. A common reason orthotics
fail is because they are prescribed for the wrong reasons; I once I
learned of a doctor who gave them to his patients with warts! Poor casting
techniques and neglecting to properly ask or analyze what type of shoes
or specific activities the orthotics will be used for also account for
failures. Additionally, if the acute problem, i.e., severe heel bursitis,
is not adequately resolved with physical therapy, ice, NSAIDs, etc.,
then the orthotics may even aggravate the problem. For many athletes, orthotics are curative and help prevent injuries. They are probably not for everyone -- which is a good thing since they are relatively expensive, ranging from $350 to $500, and are not covered by all insurance plans; for this reason, if you have a problem that interferes with your activities, an evaluation by a sports medicine professional can help ensure that you end up with a priceless panacea and not just another pricey gadget. Adam K. Spector, D.P.M. |