Do Foot orthotic Devices Work?

This post is in response to Jon Waldron , the author of the excellent Newton North blogsite. He asked me to comment on the January 17 article in the New York Times, so here are my thoughts.

In summary, the article doubts the effectiveness of foot orthotic devices (FODs) with the author backing up her points with quotes from the co-director of a human performance lab in Canada. FODs are usually discussed in terms of how they modify pronation and supination. These terms are one of the most simplified and abused terminologies in journalism today. With this article, add sensationalism to that list. It gets "eyeballs" to the Times website and sparks commentary but is not much good for more than that. This is because those eyeballs would glaze over if any attempt at what we really know about these foot motions were ever presented. These said motions describe tri-plane motions around a single joint and not a whole foot. For example pronation at the subtalar joints generally causes most of the foot to be a loose bag of bones while supination makes the bones to be a "rigid lever." However, at the neighboring mid-tarsal joints, pronation locks the foot rigid while supination causes the loose bag of bones" situation. That is the effect of only 2 of the 33 joints on basic foot motion. Dare we add in the others? How about force changes from the 100 or so muscles and tendons or the peak forces on the 26 foot bones. Don't forget the angular velocities transmitted from the rest of the body. We live in a world that is not black and white but somewhere along the spectrum of gray. The answer far less pessimistic than that of Gina Kolata article in the New York Times and far less optimistic than a foot orthotic device (FODs) chain that claims 98 percent sucess with its clients. IMHO, I see this as that classic academic/theoretical voice clashing with the clinical/practical stirred by the journalistic tempest in a teapot. For those of you that see a tipping point towards academia (Dr Benno Nigg) and away from the fee for service clinicians, think again. The article does not disclose that the good doctor has a financial interest with MBT shoes (Masai Barefoot Technology). These shoes are supposed to create instability and inefficiency in the short term to strengthen feet for the long term. Their thinking and selling point for their shoe line is that if you strengthen the muscles involved, you don't have to correct for any deformity. Hence, you can now better understand his obtuse comment that FODs are only a short term solution.

Of course foot orthotics devices work when given to someone who actually needs them and the results are long term. There is too much evidence based medicine to refute this. The kicker is that less than 10% of the injured runners that seek my care show clinical evidence that they would even benefit from FOD therapy. So we are talking about a small percentage of the general running population. Let me digress. Every runner that enters my office is screened for deviations at the subtalar and midtarsal joints as well as a host of other clinical and historical information. Dr Richard Schuster measured over 10,000 runners and found statistical correlations between these numbers and certain injuries. For example, he found a high correlation between abnormally high forefoot varus and patello-femoral syndrome. Then I take into account any structural and material "defects" in the foot or even specific things in the past medical history to honestly and profesionally decide whether a custom FOD is a viable treatment for this person or whether other avenues need to be persued. There are people "prescribed" FODs by unscupulous practioners and clinics that don't have much clinical evidence that they actually need them. People who get devices they do not need won't be helped and are sometimes hurt by such teatment. 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 nurse's aide with no formal training. The outcome of wrong presciptions lead to truly random outcomes. one of the more common errors I see is how the foot impression is captured. Clouding the issue is that how a FOD fits into a shoe can affect how well or how badly the foot functions in that shoe.

For the record, I do think that some form of strengthening of specific foot stuctures within a reasonable margin of error can be injury reducing. However, I doubt that these new "toning shoes" are that answer. In that small percentage of people that have foot deformities that cause stress and forces that exceed safety limits of what that body part can handle, something must be done to reduce it. In those special cases, custom made proper prescription FODs perform quite well.

Take two and you WILL be calling me in the morning

Use aspirin analogs (or other NSAIDs like motrin and Aleve) have been touted as half of the gold standard of the first aid of sports injuries. However such drugs might not be the gold standard it is cracked up to be.

Aspirin or acetylsalicylic acidwas dicovered in 1827 when a crude product was extracted from willow bark. In 1844, another related chemical was extracted from the oil of Gaultheria (oil of wintergreen). This related compound is still used today an an ingredient of liniments, such as Ben-Gay. Aspirin in the form we know today was introduced in 1899. This inexpensive "wonder drug became a staple of medicine chests worldwide.

An oral dose is absorbed rapidly through the stomach and small intestines and is bound to blood proteins. Apreciable amounts can be detected in the blood within 30 minutes with peak amounts in about 2 hours. It is removed from our bodies by the kidneys and, to a lesser extent, the liver.

In even low doses, asprin analogs makes platelets (a component of blood) less sticky. This is good for ailments where stickiness causes clots like heart attacks and strokes. However it is negative when talking about a fresh musculo-skeletal injury. Excessive bleeding into the injury site causes hematoma formation which can delay healing or even cause incomplete healing.

At higher doses of these drugs you mask mild to moderate pain. It takes even higher doses to reduce imflammation. However, even if you dose yourself correctly to adress the imflammation, this might not be a good thing. Researchers at the Cleveland Clinic recently published a study that adds to growing evidence that swelling actually plays a key role in healing soft-tissue injuries. The result is a classic tradeoff between short-term and long-term benefits: reducing swelling with ice or drugs may ease your pain now, but slow down your ultimate return to full strength.

When you sustain an injury, your body’s first response is to send cells called macrophages to clear away the damaged cells by literally digesting them. This initiates a complex process of repair and regeneration that triggers swelling, in part because macrophage-induced damage pokes holes in the muscle membrane, allowing fluid to rush in.

What the Cleveland study showed is that these macrophages, in addition to causing swelling, are also the primary source of “insulin-like growth factor-1,” which crucial to the growth hormone process which rebuilds our body tissues. If you take away the swelling, you also lose the growth factor.

This finding offers an explanation for clinical evidence about the double-edged effects of otherr anti-inflammatory drugs that has been mounting for several years. A review published last month in The Lancet found that injections of cortisone, a powerful anti-inflammatory steroid, brought initial relief for tendon injuries such as tennis elbow, but produced significantly worse outcomes six and 12 months later compared with patients who did nothing or performed physiotherapy exercises.

There is a use for anti-imflamatory drugs in certain situations. However, there are many more cases of abuse where the short term clouds the long term. So take two and you WILL be calling me in the morning.

Preventing Slip-ups

The first snowfall of the season usually makes for a scenic and serene run. However, the poetic karma quickly loses its luster as the winter weather wears on. The treadmill is okay for for short stretches of time. But, I don't call it the dreadmill for nothing!

Slips on ice are a product of shearing forces and lack of traction. Shear shifts a full 180 degrees during a single foot strike while running in a straight line. This is why sometimes you feet go first and other times you fall flat on your face. Even greater shear is put on the foot when you suddenly turn in either direction. So it is always important to have a heightened sense of traction awareness when making a turn.

One can improve traction in winter conditions with this little trick.

http://www.youtube.com/watch?v=us82woC7RMM

Hot tip

The late Larry Olsen was a big proponent of over-dressing for workouts whenever he could. He may have had other proprietary secrets that he took to the grave with him. However I took the overdressing tip from him in 1995 when I trained for the World Masters Cross-country Championships. The first t-shirt/shorts day of the spring, I resisted the urge to enjoy that textile freedom. Instead, I wore my Jacket and tights. I continued to dress for 10-15 degrees cooler than the day actually was until the big race (July). I race very well that year, especially in the heat.

Now, University of Oregon Human Performance Lab lends scientific support to his idea.

http://comm.uoregon.edu/archive/news-release/2010/10/heat-acclimation-benefits-athletic-performance-hot-and-cool-conditions

Stretching: The Truth

In recent years, stretching exercises have become a controversial issue, with most of the press, and nearly all of the sound bites, being against it. You would think that stretching is bad for you, rather than being a valuable tool kit in the fight against injuries and for the improvement of performance. The problem is that the buzz about stretching, as if it is one thing that everyone should do as a routine all the time, rather than being a time specific and person specific thing.




Stretching exercises are usually lumped together as one thing. This is like a tool kit of just one type of hammers. It's great if you need to pound a nail. If you need to advance a screw, you are well... just plain screwed. It is more helpful to categorize the types of stretching, in order to understand that stretching is a broad category.


A functional categorization would be:

• Active/Dynamic the opposite muscle groups fire to stretch the muscle but in an controlled understated slower way than the intended activity. Think of a ballerina warming up at the bar or a lunge exaggerated walk. When there is a bob or bounce at the end of the motion.
• Ballistic this is a term in the literature for when there is too great of a bob or bounce at the end of the active/dynamic stretch. The truth is that there is certain situations where this type has value and the key is in the acceleration and velocity of the bob. This motion can be gentle as a Tai Chi motion or as violent as the field goal kicker kicking footballs repeatedly into a net.
• Passive the body part is manoeuvred into position and held there for a set length of time. However, passive stretching requires a partner, machine, object, wall, or floor to generate external force.
• Static involves stretching a body part to a set amount without pain and holding the stretch for a set period of time. Think of a "wall push up" for stretching the calf.
• Proprioceptive Neuromuscular Facilitation PNM is a combination of passive stretching while simultaneously doing an isometric strengthening exercise.
• Yoga (means “union” in Sanskrit) and it is truly a union in that it combines active and static with proprioception overload of the central nervous system.
• Running itself has a flexibility benefit. Can you not call what happens in warm up before a hard workout a stretching exercise? Do you not feel looser in the days after certain types of workouts?

If you did exactly the same workout every day, you would quickly go stale. Staleness is the shadowy gateway to destination injury. The stretching exercises you do should be a constant work in progress that addresses the present needs of your body. Once the people with traditional media acess properly design their studies, they too will find the benefit in stretching a muscle rather than stretching the truth.

Going Bananas Over Shoes

I recently did a study for a shoe company where I was supposed to tell the anti-pronation shoes from the neutral shoes among four different shrouded shoes. It should have been a cinch for a biomechanics expert like me, right? I got all four shoes wrong...at least according to the company and their classifications of the pairs of shoes. A dart throwing chimpanzee would have scored better. Then again maybe I got them all correct and they need to monkey around to reclassify the shoes.

According to the company the stability shoes (their term for any shoe containing an "anti pronation device") were as such because of a medial post (their term for a heel midsole with harder rubber on the medial side of the shoe than the lateral). The problem is that fortunately such a "device" won't really work and limit pronation. I say fortunately because my clinical observations say less than one in ten people need heel contact pronation limited. It does not work because 99.9% of runners have contact with the ground on the lateral side of their foot. The center of gravity stays lateral till well after mid stance on most people. Then it shifts more medial to anywhere between the big toe and the 3rd toe at toe-off. The point is that the medial block is just 'along for the ride" and does not come into play. If such a gimick worked, there would be a lot of very hurt runners out there because supination is far more injurious than pronation.

Still follow me? If you do, you are doing better than the R & D person at the shoe company whose eyes glazed over when I mentioned this. So all shoes are really neutral shoes, right? Not quite. Many of the neutral shoes have extra cushioning because convention "wisdom" in the industry dictates this. Shock absorption and anti-pronation are the marketing talking points. Extra cushioning also hides a multitude of rearfoot to forefoot functional transition shortcomings. You could say it helps smooth out the ride. It also makes body parts zig when they should be zagging. The brain compensates by firing certain muscle groups eccentrically to dampen the motion and right the errant body part. In essence, it cosmetically glosses over the short term while putting extra strain on the said body parts long term. So midsoles that are too soft are like putting lipstick on your "piggies."

So, anti-pronation shoes do not really limit pronation and neutral shoes randomly affect foot function depending upon the durometer of the midsole rubber under your personal center of gravity axis lines. Running shoe classification is not a science. It is an art. It is an art to limit the random avenues in the search your proper running shoe. What this means is be careful to trust less the company classification of the shoe and trust more what past experience tells you. If a model works out for you after a few weeks of running, go out and buy a couple more pairs of that shoe before they discontinue the model. Finally, make one of those pair into your "Sherlock shoes.

If the shoe fits...

The funny thing is that if shoes met the individual needs of the runner in a better fashion, this whole shod versus unshod discussion would become a moot point. However, that is a whole other rant for another day.

Another day has finally arrived. So let me attempt to tackle a very complex issue in the most distilled form of an explantion.

My first training shoes I ever owned for running were purchased in my second year of running for 2 bucks (1969). For the first year, I used my regular sneakers. Those running shoes had a canvas upper, narrow heel, flimsy arch, and no cushioning. Such characteristics are the complete antithesis to running shoes today. Yet somehow, I managed to run injury free for the almost 2 years I ran in that model. The same was true for all of my teammates. There were “luxury” trainers available from Adidas or Pumas. But, most of our pennies were saved to buy the spikes needed to race on the cinder tracks we had in that era. Meanwhile, the road racing groundswell was in the making. Distance Running news became Runner’s World Magazine. Bill Rodgers and Frank Shorter were the pied piper icons to fuel the emerging running boom fire. In the late 70’s RW did their first comprehensive shoe review. A human performance lab did several physical characteristic tests. Based on this data, the shoes were ranked from one to five stars. The idea was innovative and with good intentions. But we all know that many times the road race to hell is paved with good intentions. Sales of 5 star shoes skyrocketed while excellent shoes that didn’t test well were ranked 1 or 2 stars and were suddenly discontinued. For example, one test in the study measured absorption of energy of a weight dropped onto the heel of a shoe. So, here is the classic en vitro versus en vivo scientific principle. Measurements in the test tube in the lab do not reflect what is happening in the real world. This only measures initial impact in the shoe and says nothing about the angular velocities and peak and sustained forces on tendons, muscles, bones and ligaments in the human body. Shoes that were not right for many people flourished and led to the nuclear arms race of which company could produce the biggest attenuation of the initial impact force.

Dr. Daniel Leiberman’s recent studies point out that heel strike causes an initial impact transient, a nearly instantaneous and large increase in force that occurs as the heel comes to a sudden stop upon impacting the ground. The shoe reduces the force by about 10% and slows the rate of loading considerably. This, in addition to distributing the impact force over a larger area of the rearfoot, makes it comfortable to exaggerate heel strike leading to the en vivo stress on the human body.

Shoe reviews do not shoulder all the blame. The consumer who is enthralled with the latest gimmick fuels the diversion away from what is really best for them. Back in the 60’s, Keds had the magic wedge which “make you run faster and jump higher.” It quickly became apparent to shoe companies that you put an untested gimmick (a few weeks use by a wear tester at best) on the market. The Nike “air” is classic example of this. It was sealed gas tubes enclosed in a polyurethane midsole. The Tailwind was a successful selling shoe even though instability injuries were rampant with the shoe. The Columbia attempted to address this instability by added a more stable EVA, but like the spaceship Columbia in its ad, it too, crashed and burned. It took several renditions of the air gizmo before the bugs were worked all. If the consumer wasn't so willing to be the long term ginea pig for an idea they like, gimmicks and gizmos would be an insignificant factor.

Running shoes are supposed to protect the foot. However, running shoes are also a business. They are mostly part of huge publicly traded companies whose concerns are market share, sales, net profits, free cash flow, and everything that goes along with a myopic shareholder quarterly report.

This adds pressure to have shoes on the minimum number of lasts to accommodate the maximum number of people. Many companies copy another company's best selling lasts. This leads to less variation among the brands and even less models to address the subtle genetic diversity in all the feet out there. Not only at the corporate level but also the retail level where stores have only so much capital to stock their shelves. Improper fit leads to abnormal function.

Now add to the fact that Sport Trend magazine did a survey study in the late 80's and found that 80% of the running shoes purchased will never even be used for running.

You can see reasons for wayward goals and distractions of the health quality of running shoes. This is why the barefoot running community knows that unshod feet often outperform the latest couple hundred dollar smart shoe.