January 18, 2011

Do Orthotics Work?


I don't wear orthotics, but if I did, I'd like to feel some confidence in their effectiveness, preferably backed up by plenty of research.

It seems, however, that there's some mystery about orthotics, at least that's the suggestion of an article in the January 17th NY Times summarizing the work of Benno M. Nigg. Dr. Nigg is a professor of biomechanics and co-director of the Human Performance Lab at the University of Calgary in Alberta, and he claims that the research is mostly inconclusive about whether orthotics work, and if they do, how they actually benefit athletes who use them.

To be sure, runners seem to like them. I'm pretty confident that among my readers there are runners who will swear that orthotics have helped them correct biomechanical issues and have allowed them to run injury-free. I'm willing to accept that evidence at face value: orthotics do help some people.

But here's one mystery: In Dr. Nigg's studies, he found there was no way to predict the effect of a given orthotic on an athlete. The article says:

"One person might respond by increasing the stress on the outside of the foot, another on the inside. Another might not respond at all, unconsciously correcting the orthotic’s correction."


Here's another mystery: assuming there is a biomechanical problem to correct, there seems to be little agreement about the best way to make an insert to achieve the desired effect. I.e., if the same runner visits a number of different certified makers of orthotics, he or she might come away with devices that take quite different approaches to correcting the perceived biomechanical flaw.

The article asks: what do orthotics actually do? Well, they don't seem to change the way the skeleton moves, but they do seem to make certain muscles work significantly harder (or less hard), and increase (or decrease) stress on certain joints. That sounds promising, but again, there seem to be few rigorous studies to show how to take advantage of these effects.

The article never mentions the issue of anatomical asymmetry -- having legs of different lengths or feet of different size. I found myself wondering whether studies might reach different conclusions with a more set of subjects who shared some such trait.

I suppose one hopeful conclusion came from one study of Canadian soldiers, in which half were allowed to choose from several different types of orthotics and the other half continued with none. The group that chose their own seemed to have about half the injuries of the control group. But here's yet another mystery: "...there was no obvious relation between the insert a soldier chose and his biomechanics without it."

Well, I suspect that the fault might lie with the sensitivity of the tests, but what do I know.

Hey wait, I haven't heard from Bob Chasen for a while. Unlike me, he is a professional and has thought about this stuff for thirty years. (If you have't read his blog, Taking Things in Stride, you should.) If you're out there Dr. Bob, would you care to comment? What does an orthpedist think about this unorthodox take on orthotics?

3 comments:

Dr Bob said...

Jon,

Pronation and Supination of the foot is one of the most simplified and abused terminologies in journalism today. It gets "eyeballs" to the site and sparks commentary but is not much good for more than that.

Here is a "cliff notes" version of my answer. I will try to work on a nore thorough version when I have more time (weekend?) and put it on my blog.

Of course foot orthotics devices (FODs) work when given to someone who actually needs them. The kicker is that less than 10% of the injured runners I see show clinical evidence that they would even benefit from FOD therapy.

There are people "prescibed" FODs by unscupulous practioners and clinics to people that don't have much clinical evidence that they actually need them. This is further fed by patients that think, they need them or maybe just want them.

Then there is the group of people that show some evidence of needing correction but are given the wrong prescription. One area sports clinic had their FODs made by a 7 dollar per hour nurses aide with no formal training

Clouding the issue is that how a FOD fits into a shoe can affect how well or how badly the foot functions.

Jon Waldron said...

Dr. Bob -- Thank you for offering your perspective on this article. I hope you do get a chance to write about FODs at more length. I'll look forward to having my views corrected!

Tom said...

From personal experience I've found that orthotics can be both incredibly effective or incredibly ineffective.

Ever since I began running as a thirteen year old freshman, I have never gone more than 12 weeks of training without having a serious breakdown. During all of this time, I tried almost everything to stay healthy, including orthotics and all of the fad shoes. Well, last winter I both paid a visit to Dr. Bob and decided to start running in a minimalist shoe, both of which I'd never done before. The outcome has been terrific. Ever since I began running in Dr. Bob's incredibly lightweight and unobtrusive orthotic, paired with the Saucony Kinvara -- I have been more or less injury free. In the last 8 months of 2010 I averaged 90 miles per week, or 55 miles per week more than I've ever averaged over that length of time.

To me, I believe that if you are injury prone -- you need to see an expert on the problem, and not just jump to the conclusion that orthotics are the be all end all cure of injuries. For running related injuries, especially in the podiatry field, I believe that no one can beat the experience and understanding of Dr. Bob. Once you get a grasp on your issues, a true grasp, you will be amazed at the amounts of training and stress the human body is designed to adapt to.