SAN FRANCISCO — There's no truth in the belief that a person can become dependent on orthotic soles—in fact, orthotics can be very useful in correcting certain foot problems, according to Dr. Anthony Luke, at a conference on sports medicine sponsored by the University of California, San Francisco.
“Do you want to wear more comfortable shoes, or do you want to wear crummy shoes? Because that's really all you are doing,” said Dr. Luke of the department of orthopedic surgery at the university.
“You're putting an insert in. You're not doing surgery on [patients], and you're not taping it to their foot for the rest of their lives. I don't know how you necessarily become dependent, [although] I certainly run into people who really love their orthotics and never want to go without them,” he commented. It is not certain, however, that $400 custom-made orthotics are substantially better than over-the-counter brands available in stores.
The primary purpose of orthotics is to improve the efficiency of a person's gait by helping to control excessive or unwanted motion. It's also possible to use them to relieve the weight load on sensitive areas of the foot. If a patient has metatarsal pain, for example, then pads can be added to the orthotic to decrease pressure on the painful area.
To determine whether a runner would benefit from orthotics, one should first examine the foot when it's not bearing weight and when it's in the subtalar neutral position—neither pronated nor supinated. Many methods for determining subtalar neutral have been proposed, and there is controversy in the literature about which is best.
Dr. Luke said that he has the patient lie prone on the examining table, then lifts the patient's foot by the fifth metatarsal. He then places his other hand on the opposite side of the ankle and rocks the foot back and forth, causing the calcaneus and the talus to invert and evert. The aim, he said, is to “find that position where the talus is no longer banging into my fingers. That's going to be subtalar neutral.”
Next, he looks at the Achilles' tendon and the angle of the calcaneus. A heel that is turned inward indicates a heel varus, which suggests the patient has trouble unlocking the midfoot. Conversely, if the heel is valgus, then the patient is starting off in a bad position, and it is no wonder they're pronating, he said.
Orthotics can be customized to correct specific problems. For example, they can include a lift if there is a discrepancy in leg length. And they can have posts added in areas needing special support to achieve a subtalar neutral position.
A number of different materials can be used to construct orthotics, but Dr. Luke noted that he is suspicious of especially rigid materials. “It's kind of like running on a very hard surface.”
But before prescribing custom orthotics, Dr. Luke suggested that patients try an over-the-counter pair. There's little compelling evidence that custom orthotics are significantly better than those that are bought over the counter—and custom orthotics are as much as 10 times more expensive.
If nothing else, the cheaper orthotics can be used as testers, and although the correction may not be perfect, the patient will likely experience at least some improvement.
An easy way of testing whether an orthotic is doing its job or not, is to have the patient take it out of the shoe, put it on the floor, then stand on it. The doctor should then compare the patient's stance in the orthotic with the stance when he or she is standing on the floor. If the device corrects a patient's pronation (for example) in the static position, then there is a good chance it will correct the pronation in motion. However, if the orthotic doesn't even correct the static position, then it will probably not be that useful for a patient in motion.
Orthotics can be customized to help correct a patient's specific problem, such as pronation or a discrepancy in leg length. Courtesy Dr. Anthony Luke