Thursday, October 28, 2010

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.

Sunday, October 10, 2010

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.

Sunday, June 13, 2010

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 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.

Sunday, May 16, 2010

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.

Friday, February 12, 2010

The Great Red Hope

A recent experimental treatment for tendinosis was found to no more effective than injecting salt water.

The hopes of many were raised when the media put forth articles such as these:

It sounds seductive to take extracts of the athlete's own blood and inject them into the injured area to heal an injured tendon. Most chronic tendon injuries are as a result of a complex process called tendinosis. So what is the cliff notes version of tendinosis? The suffix "osis" implies a pathology of chronic degeneration without inflammation. The main problem for someone with tendinosis is failed healing, not inflammation; tendinosis is an accumulation over time of microscopic injuries that don't heal properly. Although inflammation can be involved in the initial stages of the injury, it is the inability of the tendon to heal that perpetuates the pain and disability. Most of the pain associated with tendinosis probably comes not from inflammation but from other irritating biochemical substances associated with the injury. Biochemically, it is the replacement of injured tendon collagen with the wrong kind of collagen. Normal tendons and ligaments consist mostly of Type I collagen, with smaller amounts of Type III collagen. When you get tendinosis, some of your collagen is injured and breaks down. Your body tries to heal the tendon, but when you have chronic tendinosis your body doesn't repair the collagen properly. The tendon loses its spring like characteristics which triggers more abnormal forces in a degenerating vicious cycle.

I know of many a recent athlete that opted for this procedure, which is not covered by medical insurances, only to have found they wasted valuable time and money.

The results of this double blind study are discussed here:

The new study included 54 people with chronic Achilles tendinopathy who participated in an exercise program to stretch their tendon while contracting their calf muscle. The exercise program was coupled with either a PRP injection or a saline (dummy) injection. Researchers measured pain and activity levels using a standardized tool at baseline, 6, 12, and 24 weeks.
Although there was an improvement seen among individuals treated with PRP after 24 weeks, it was no different than what was seen among those who received the placebo injection.

So what is a poor injured athlete to do? Surgery does work but takes 1 to 3 years to get "back to form." Keep in mind that "form" is slower than the pre-surgery form. I find the best option is to start with off-loading the tendon. A special tape is applied every 3 to 5 days to reduce peak forces in the tendon. Varying amounts of eccentric strengthening exercises are also helpful. Cortisone type steroids are a complete no no for this problem. However some people gain benefit from injection of an extract form the Arnica Montana plant. Then identify the hidden causes the are overloading the tendon. This takes a thorough, analytical, and diligent sports medicine physician. If you could do it yourself, you wouldn't be at this level of chronic injury, now would you?

Fighting tendinosis is a complex war, not a single battle. There is no magical silver bullet. So use all the resources at your disposal and increase a victorious outcome.