orthotics vs arch supports the controversy continues

Most drivers don’t think much about spark plugs and carburetors. They just want their vehicles to run, leaving the details to their mechanics. Most homeowners trust electricians to worry about voltages and alternating currents. They just want their lights to come on. In the same way, most patients who use medical devices just want the devices to work. Knowing how they work is the domain of clinicians and researchers. Unless, that is, the medical device is a foot orthotic.

According to Benno Nigg, professor of biomechanics and codirector of the Human Performance Laboratory at the University of Calgary in Alberta, even medical experts aren’t sure exactly how orthotics relieve pain or prevent injury. “Orthotics can work and can have fantastic effects, but we don’t know how they work,” says Nigg.

The growing orthotics market could reach annual sales of US$4.7 billion by 2015, according to Global Industry Analysts, Inc. (www.sfgate.com/cgi-bin/article.cgi?f=/g/a/2011/01/13/prweb8061575.DTL). Orthotic devices are used by the public primarily to relieve pain, and by athletes to prevent injury. It is also a diverse business, including everything from custom products made from high-tech materials to inexpensive insoles.

Though prescribed in large numbers by podiatrists and orthotists, clinicians still struggle to determine which type of orthotic will work for a particular patient. In his new book, Biomechanics of Sport Shoes, Nigg describes sending a long-distance runner to five orthotics makers to seek help correcting a problem with pronation. Each made a very different type of insert, varying in thickness, hardness and other ways.

“What this means is that specialists come to completely different conclusions on what to do,” says Nigg. “It also shows that we don’t really understand what we do.”

One hypothesis is that orthotics correct skeletal alignment problems, though Nigg says there is no evidence to support that proposition. Rather than moving bones around, it is more likely that orthotics affect muscle activity, he says. Figuring out how they affect muscle activity — and how to correct activity that is causing pain or injury — could lead to more consistent prescribing of orthotics.

“Maybe we should not think of pushing the skeleton around, but rather about finding ways to give signals to the body to do the right thing,” says Nigg.

Dr. Michael Nirenberg, a podiatrist in Crown Point, Indiana, says he is not surprised by the lack of consensus on how orthotics work. “There isn’t even a consensus on what an orthotic is,” he says, noting that the term is used to describe both pricey custom-made inserts and cheap insoles available at any drugstore.

Determining which orthotic will work best for a patient is difficult, says Nirenberg, because so many factors come into play. Even if two patients are similar in many ways — weight, gait, foot structure — they may still experience very different outcomes after using similar orthotics. “You can’t guarantee anything is going to work for everyone, because people are so variable,” he says. “Orthotics can do amazing things for many people, but not for everyone.”

The basic function of an orthotic is to put the foot into a better position, which alleviates pain, says Nirenberg. If a muscle is strained or hurting, a properly chosen orthotic will do some of the muscle’s work for it, thereby reducing its workload and bringing relief. Of course, giving muscles a permanent vacation also has a down side.

“When you brace the foot, that may alter the function of the foot for the better, but in doing so it negates the need for many of the muscles in the foot to do anything,” says Nirenberg. “Common sense tells us that if you don’t use a muscle, it’s going to weaken.”

When visited by a patient in pain, Gordon Ruder, a practising orthotist and the coordinator of the prosthetic and orthotic programs at George Brown College in Toronto, Ontario, won’t prescribe orthotics right away. First, he will recommend such things as better shoes, strength training, stress reduction or lifestyle changes that could alleviate the problem. Sometimes, however, these things aren’t enough.

“You might have chronic pain that can’t be managed by other means, and you still need to work 12-hour shifts, and you can’t change jobs to one that will stop you from spending time on your feet,” says Ruder.

In such cases, Ruder will recommend orthotics, though, like others in his field, he warns that picking the right type for a patient is not an exact science. “It’s not as simple as replacing brake pads on a car after they’ve worn out,” he says. “The human body doesn’t work like that.”

As a researcher, he would like to see more resources put into studying orthotics. Existing research has been lacklustre, mainly because it is difficult to quantify the biomechanical changes that result from wearing orthotics. There is a need for more-sensitive tools that are capable of detecting these subtle changes, says Ruder. “I very much want to see research become a bigger part of what we do.”

Bruce Werber DPM, FACFAS

10900 N. Scottsdale Rd, Suite 604

Scottsdale, AZ 85254

480-948-2111

www.inmotionfootandankle.com

arch supports, plantar fasciitis

The extent to which stretching and strengthening exercises successfully address plantar fasciitis continues to be a matter of debate among practitioners. Variables known to be associated with the condition include obesity, reduced ankle dorsiflexion, and work-related weight-bearing.

A 2008 study in Skeletal Radiology, however, added atrophy of the abductor digiti minimi muscle to the list, although it remains unclear whether the atrophy was the cause of fasciitis or its result. Similarly, a 2003 study from the University of North Carolina found that subjects with fasciitis had weaker toe flexors than did controls, but the cause and effect was unclear.

An author of that study, Michael Gross, PT, PhD, a professor of physical therapy, explained the dilemma.

“If someone already has fasciitis, and they’re guarding so that they don’t push off forcefully, that could lead to weakness of the toe flexors,” he said. “On the other hand, if they have a preexisting weakness, that could contribute to the onset of fasciitis.”

And although no controlled trials demonstrate the efficacy of exercises, Gross believes a case can be made for stretching of both the plantar fascia and the Achilles tendon for some patients.

“Heel raises will strengthen the extrinsic muscles of the foot,” he said. “The intrinsic muscles may benefit from toe grasping, which you can do by putting your foot on a weighted towel, then repeatedly curling your toes to drag the weight and the towel toward you.”

Walt Reynolds, CSCS, CPT, a personal trainer in Lansing, MI, who has written on the Web about exercises for fasciitis, still uses them occasionally with patients but has moved toward a more holistic approach.

“I work with a lot of runners, and the issues they face are largely form-related,” he said. “As a result, I now approach training on the ’5S’ model—speed, strength, stamina, suppleness, and skill.”
Reynolds said athletes with fasciitis may experience pain in the affected foot, but the root of the problem often lies elsewhere.

“Stretches may deal with the fasciitis to a point, but they won’t address the problem that actually drives it,” he said.

When Reynolds does suggest stretching, he favors a rotational hamstring stretch, a tri-plane Achilles stretch, and a rotational plantar fascia stretch. (Detailed descriptions can be found at www.sportsinjurybulletin.com/archive/plantar-fasciitis-exercise.html.)

“When you add a rotational component, you get a more functional stretch,” Reynolds said. “Most people consider the ankle joint as working primarily in the sagittal plane, but all motion is ultimately in all three planes, and transverse-plane motion may be the most significant.”

Strengthening can simply be a matter of gait. Researchers from the German Sport University in Cologne reported at the 2005 International Society of Biomechanics conference that runners who warmed up for a few minutes with minimalist footwear increased the strength of their metatarsophalangeal joints and the cross-sectional area of their flexor hallucis, flexor digitorum, abductor hallucis, and quadratus plantae muscles.

“My theory is that we have conditioned our feet to be lazy by the overuse of arch supports,” said Irene Davis, PT, PhD, former director of the Running Research Laboratory at the University of Delaware and now with the department of physical medicine and rehabilitation at Harvard Medical School.

Although Davis recommends the usual exercises—toe grasping and heel raises (she finds the latter particularly effective if done on stairs, so that the subject begins with the heels lower than the forefoot)—she considers walking at least as important.

“One of the best exercises is to use your foot in a functional way,” she said. “If people place greater demands on their feet in a slow, progressive way, I think we can reduce the incidence of plantar fasciitis.”

yes stretching is extremely important, utilizing appropriate orthotics is also important, buying arch supports at the store when not fitted for your foot is a waste of money.

If arch supports/orthotics are working correctly they will help strengthen your foot, but if you buy poorly fit orthotics then you are wasting your time and hurting your fee.

Bruce Werber DPM, FACFAS

10900 N. Scottsdale Rd Suite 604

Scottsdale, AZ 85254

480-948-2111

www.inmotionfootandankle.com