Think back to your first triathlon. Before you started training, you probably talked to friends with experience, joined a training group, or asked the local store for more information. You might have read some magazines or books, or browsed information on-line. For some reason, though, people don’t seek lessons for running since they believe that their strength and form is just dandy.
Ironman.com is proud to present a series of “Running Modules” written by Newton’s Director of Research and Education, and seven-time Adventure Race World Champion, Ian Adamson.
Adamson’s athletic resume proves he can endure like no one else on the planet – in addition to the seven world titles, he’s won 18 Adventure Race Championship titles, set three Guinness World Records and is a three-time medalist at the ESPN X-Games. He did his first triathlon in 1984. With a background in both mechanical engineering and sports medicine, Adamson brings a unique perspective to the world of running biomechanics, which he’ll share with us every month here on Ironman.com.
Here’s the thing: most runners in our population will get injured if they run consistently for a prolonged period of time. Studies show that the majority of runners – somewhere between 20 and 80 percent – will get injured in any given year1. This is a pretty big risk for any activity and, I’m guessing, most people would not rock climb, ski or catch a plane if they were told that there was a 50 percent chance that they would suffer injury.
Paradoxically, most (sensible) people pursue knowledge and training before attempting a skill that involves the possibility of injury, but not for running. Consider scaling a 20,000-foot peak, parachuting out of an airplane or learning how to swim for the first time. Lessons, check. Practice, check. Proper equipment, check.
Fortunately, as triathletes, we are students of technique and love our equipment and technology. Successful IRONMAN athletes work on their form on the bike, in the pool and many transfer this to the run. Yet running injuries are still prevalent, which begs the question, why?
Humans are extraordinarily good distance runners and have done so (without footwear) for virtually the entire length of human evolution2. As you might imagine, injured runners did not survive, so the emergence of running injuries is a relatively new phenomenon. The current body of evidence in science indicates running form and footwear as primary causes injury. Over the last few years it has become apparent that most runners in affluent populations (using a “western gait” style), run with a technique that results in high loading rates. High loading rates are believed to increase risk of injury.
One way to describe the western gait is habitually shod running3. Populations that do this are a minority of the human population, by some estimates about one in seven humans on the planet. In other words, the one billion who have enough money to buy running shoes.
In fact, modern running shoes, those with midsole cushioning, appeared in the 1960s, while running as a recreation became popular in the 1970s. Industry estimates show there are around 30 million regular runners in the United States (those who run at least three miles, three times per week), or about 10 percent of the population. This is representative of other first world countries, so a reasonable approximation for the number of recreational runners in the current human population is 10 percent of 1 billion, or 100 million.
Having lived, worked and raced in most of Asia, Africa, the Pacific Rim, Europe and the Americas over the past 20 years, it is clear that most humans don’t run like us wealthy western folk (western hemisphere that is, not cowboys), nor do they suffer the same types or rates of injury.
One important factor for western runners is our lifestyle. Humans evolved to spend six to eight hours a day performing functional movements. That is, standing, walking, carrying, lifting and generally being active. It is only since the industrial revolution that humans became sedentary, which has lead to problems, including a significant reduction in longevity4. Today the average number of hours of daily activity for our population is closer to 30 minutes, with most of our time sitting. Anthropologists have strong evidence that there has been more than five million years of bipedal evolution leading to humans (the last 200,000 years). Time score: evolution 5,000,000, modern lifestyle 250, modern running shoes 40.
So what does all this have to do with running speed, efficiency and rates of injury? Quite a lot. When we examine the essential requirements for runners, most athletes in our population fail. This series will explain what we need as runners, simple evaluations, diagnosis, treatment and proscription to run better and with reduced injury risk.
As a start, it is useful to understand the basic requirements for a human to be able to run efficiently. Lets start with some basic gait mechanics. In running, we alternate between a stance phase and flight phase each step. In effect we hop up and forward by pushing down and back onto the ground every step. If you video yourself running (from the side) you can see how this happens.
One consequence of the flight-stance cycle is oscillating vertical motion. In flight phase we are unsupported by the ground, gravity takes hold and we fall back to the ground. The resulting force of pushing off the ground to get back in the air is equivalent to two to three times your body weight every step on level ground (less up a hill and more down a hill). Step rate and other factors come into play, but the net result is a lot of force on your body every time your foot is in contact with the ground.
Maximum load actually occurs in mid stance, not at contact (or foot strike) as many people think, since you body has not fallen to its lowest point. It is only when you change direction in the vertical axis that the force tops out. Forces occur in all three planes when running, with a little over one-body weight side-to-side (laterally) and a bit more front to back (sagittally.) Anatomy for runners, by Jay Dicharry, describes clearly, and in detail, the forces involved in a running gait, something we will examine more in subsequent articles.
To see what happens for yourself, try doing a series of shallow single leg squats (with good posture and foot flat to the ground) until you fatigue. This is simulating a running gait, but with very low force, close to one body weight. Now consider doing this 750 times on each leg every mile (at about 7 mph and about 90 steps per leg per minute.) This requires strength, balance, coordination, range of motion at the joints and endurance. We can simplify this to stability (strength and balance), mobility (coordination and ROM) and aerobic development (or fitness).
Do you have the stability, mobility, strength and fitness to do this every step of a long run? If you can’t maintain perfect balance, alignment and coordination in the single leg squat exercise above, the answer is probably no. If this is the case, then contemplate what might happen to your joints and the supporting musculature and connective tissue as you load two to three times your bodyweight on them every step during a run.
Here are three things to look for in the single leg squat exercise:
1. Is your knee stable and does it track straight?
2. Does your pelvis stay level (no hip drop, lift or rotation)?
3. Can you maintain alignment of your body column, all joints and limbs head to toe?
Think back to your first triathlon. Before you started training, you probably talked to friends with experience, joined a training group, or asked the local store for more information. You might have read some magazines or books, or browsed information on-line. For some reason, though, people don’t seek lessons for running since they believe that their strength and form is just dandy.
Ironman.com is proud to present a series of “Running Modules” written by Newton’s Director of Research and Education, and seven-time Adventure Race World Champion, Ian Adamson.
Adamson’s athletic resume proves he can endure like no one else on the planet – in addition to the seven world titles, he’s won 18 Adventure Race Championship titles, set three Guinness World Records and is a three-time medalist at the ESPN X-Games. He did his first triathlon in 1984. With a background in both mechanical engineering and sports medicine, Adamson brings a unique perspective to the world of running biomechanics, which he’ll share with us every month here on Ironman.com.
Here’s the thing: most runners in our population will get injured if they run consistently for a prolonged period of time. Studies show that the majority of runners – somewhere between 20 and 80 percent – will get injured in any given year1. This is a pretty big risk for any activity and, I’m guessing, most people would not rock climb, ski or catch a plane if they were told that there was a 50 percent chance that they would suffer injury.
Paradoxically, most (sensible) people pursue knowledge and training before attempting a skill that involves the possibility of injury, but not for running. Consider scaling a 20,000-foot peak, parachuting out of an airplane or learning how to swim for the first time. Lessons, check. Practice, check. Proper equipment, check.
Fortunately, as triathletes, we are students of technique and love our equipment and technology. Successful IRONMAN athletes work on their form on the bike, in the pool and many transfer this to the run. Yet running injuries are still prevalent, which begs the question, why?
Humans are extraordinarily good distance runners and have done so (without footwear) for virtually the entire length of human evolution2. As you might imagine, injured runners did not survive, so the emergence of running injuries is a relatively new phenomenon. The current body of evidence in science indicates running form and footwear as primary causes injury. Over the last few years it has become apparent that most runners in affluent populations (using a “western gait” style), run with a technique that results in high loading rates. High loading rates are believed to increase risk of injury.
One way to describe the western gait is habitually shod running3. Populations that do this are a minority of the human population, by some estimates about one in seven humans on the planet. In other words, the one billion who have enough money to buy running shoes.
In fact, modern running shoes, those with midsole cushioning, appeared in the 1960s, while running as a recreation became popular in the 1970s. Industry estimates show there are around 30 million regular runners in the United States (those who run at least three miles, three times per week), or about 10 percent of the population. This is representative of other first world countries, so a reasonable approximation for the number of recreational runners in the current human population is 10 percent of 1 billion, or 100 million.
Having lived, worked and raced in most of Asia, Africa, the Pacific Rim, Europe and the Americas over the past 20 years, it is clear that most humans don’t run like us wealthy western folk (western hemisphere that is, not cowboys), nor do they suffer the same types or rates of injury.
One important factor for western runners is our lifestyle. Humans evolved to spend six to eight hours a day performing functional movements. That is, standing, walking, carrying, lifting and generally being active. It is only since the industrial revolution that humans became sedentary, which has lead to problems, including a significant reduction in longevity4. Today the average number of hours of daily activity for our population is closer to 30 minutes, with most of our time sitting. Anthropologists have strong evidence that there has been more than five million years of bipedal evolution leading to humans (the last 200,000 years). Time score: evolution 5,000,000, modern lifestyle 250, modern running shoes 40.
So what does all this have to do with running speed, efficiency and rates of injury? Quite a lot. When we examine the essential requirements for runners, most athletes in our population fail. This series will explain what we need as runners, simple evaluations, diagnosis, treatment and proscription to run better and with reduced injury risk.
As a start, it is useful to understand the basic requirements for a human to be able to run efficiently. Lets start with some basic gait mechanics. In running, we alternate between a stance phase and flight phase each step. In effect we hop up and forward by pushing down and back onto the ground every step. If you video yourself running (from the side) you can see how this happens.
One consequence of the flight-stance cycle is oscillating vertical motion. In flight phase we are unsupported by the ground, gravity takes hold and we fall back to the ground. The resulting force of pushing off the ground to get back in the air is equivalent to two to three times your body weight every step on level ground (less up a hill and more down a hill). Step rate and other factors come into play, but the net result is a lot of force on your body every time your foot is in contact with the ground.
Maximum load actually occurs in mid stance, not at contact (or foot strike) as many people think, since you body has not fallen to its lowest point. It is only when you change direction in the vertical axis that the force tops out. Forces occur in all three planes when running, with a little over one-body weight side-to-side (laterally) and a bit more front to back (sagittally.) Anatomy for runners, by Jay Dicharry, describes clearly, and in detail, the forces involved in a running gait, something we will examine more in subsequent articles.
To see what happens for yourself, try doing a series of shallow single leg squats (with good posture and foot flat to the ground) until you fatigue. This is simulating a running gait, but with very low force, close to one body weight. Now consider doing this 750 times on each leg every mile (at about 7 mph and about 90 steps per leg per minute.) This requires strength, balance, coordination, range of motion at the joints and endurance. We can simplify this to stability (strength and balance), mobility (coordination and ROM) and aerobic development (or fitness).
Do you have the stability, mobility, strength and fitness to do this every step of a long run? If you can’t maintain perfect balance, alignment and coordination in the single leg squat exercise above, the answer is probably no. If this is the case, then contemplate what might happen to your joints and the supporting musculature and connective tissue as you load two to three times your bodyweight on them every step during a run.
Here are three things to look for in the single leg squat exercise:
1. Is your knee stable and does it track straight?
2. Does your pelvis stay level (no hip drop, lift or rotation)?
3. Can you maintain alignment of your body column, all joints and limbs head to toe?
Watch five-time World Champion and Kona course record holder Craig Alexander’s running form (above) from the side and from behind, and notice how he maintains near perfect alignment at all points during his gait cycle.
Next month: Stability and balance
References
1. van Gent et al, Incidence and determinants of lower extremity running injuries in long distance runners: a systematic review, Br J Sports Med 2007:41
2. Dennis M. Bramble & Daniel E. Lieberman, Endurance running and the evolution of Homo, Nature 2004:432
3. Lieberman et al, Foot strike patterns and collision forces in habitually barefoot versus shod runners, Nature 2010:463
4. Veerman et al, Television viewing time and reduced life expectancy: a life table analysis, Br J Sports Med 2012:46
http://www.ironman.com/triathlon-news/articles/2013/02/newton-running-module-1.aspx#ixzz2M9HoeOXY
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