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Wednesday, September 26, 2007

Running technique Part II: Biomechanics of running and Pose

Today is Part 2 of our series looking at running technique. So far, it's been an extremely interesting and challenging series to write, and we've received some really interesting stories and comments from readers. That's something we're very grateful for, and many of those comments are incorporated into the posts you'll read over the next few days.

What is probably a bit confusing is that because this series is being done one post, one day at a time, I've not yet really put out there my own explicit position on this, and so many times, we receive comments which I agree 100% with, but which haven't been expressed openly in the posts (yet!). So I thought that perhaps I should come out and give my position on running technique, rather than sitting on the fence until all the evidence is discussed, and then in the next three posts, we'll look at some of that evidence (and opinions - this is a blog after all, not a scientific journal!) which has led me to this position.

Is "natural" running technique optimal? Can it be improved? And should it be taught?

My opinion is that good running technique is:

  • First learned naturally, then;
  • Refined through practice, and then;
  • Subtle changes can be taught through instruction on a case by case basis.

When I write that running is a 'natural' activity, bear in mind that "natural" does not mean "optimal". So while everyone can run, not everyone runs WELL. The key question is whether one can (or should) be instructed in a technique. That is, after all, what both Pose and Chi claim to do. My position is that the instruction of a generic, "one size fits all" running technique is likely to create more problems than it fixes (as we'll see in tomorrow's post). But that does NOT necessarily mean that there are not principles and concepts from those running techniques that are sound.

So we have received some very interesting emails, including one that the Kenyans run the best, probably because they have to run barefoot, and the biomechanics of barefoot running and quite different to those when running in shoes. Also, people have written of their experiences in learning a better running technique through repetition and practice. These interesting and correct stories illustrate two points:

1. Running technique can be improved vastly by training. Just as a tennis player has to hit many balls and a golfer spends hours on the range, so too, running properly requires practice.

2. Running technique does not have to be "taught". Rather it is learned through practice, circumstances and then implementation.

Of course, there is a chance that people will learn or develop bad habits. And this is where the instruction and application of certain technical drills can make a difference. An informed coach, a knowledgeable observer, or even an intuitive runner can adapt and modify technique, so that it conforms with a better theoretical model for running. I believe there is a better way to run, but that is NOT the same thing as saying there is ONLY ONE WAY TO RUN. We are all different, every case is different, and so the idea that one running technique (be it Pose or Chi or Kenyan style) is the way to go seems over-simplified. Instead, treat each case on its merits, knowing that small changes can produce noticeable results. But it's not the same change every time.

And so that's my position. What we'll do next, is look in a bit more detail at the theory behind the running techniques. I will focus on Pose, because I'm far more familiar with it. But everything will be taken from the respective websites, so that I'm not misquoted anything. That way, it's more objective. So let's have a look at just what Pose is?

The biomechanical basis for Pose running

The Pose running method is named after the characteristic "running pose" which is described as "optimal". From the website:

"The Running Pose is a whole body pose, which vertically aligns shoulders, hips and ankles with the support leg, while standing on the ball of the foot. This creates an S-like shape of the body. The runner then changes the pose from one leg to the other by falling forward and allowing gravity to do the work. The support foot is pulled from the ground to allow the body to fall forward, while the other foot drops down freely, in a change of support.

So effectively, the idea behind Pose is two fold:

1. You create forward movement by positioning the body in such a way that you FALL forward - using gravity to create movement, and

2. You move the legs through PULLING, rather than the more common thought of DRIVING the knee forward and swinging the knee forward.

Again, from the website: "This simple sequence of movements: the fall and the pull, while staying in the pose, is the essence of running technique."

So that is it in a nutshell. I'm selling it short, of course, because there is more to it than just this. But basically, what the technique says is:

  • Lean forward, not with the shoulders but from the ankles. You have to keep the body in a straight line from the ankles, to the knees, to the hips to the shoulders. Imagine a telephone pole falling over - it doesn't bend and then fall, it falls from the ground - the ankles. Imagine you're a tree being blown by the wind - you 'fall' from the ground contact point, not by bending at the hips and dipping your shoulders.
  • With your hips (which is where your centre of mass is) in front of your contact point with the ground (your feet), you are in a position to fall. That's where gravity acts on the body - we don't need to worry about getting into the physics of the x-component and so on of gravity.
  • All that is left now is to leave the ground - you do this by pulling the foot up off the ground and allowing gravity to return the other foot to the ground. You've then changed the point of support, and the running movement is then just a sequence of changes of support.

If you consider the alternative, the classically thought of (or expressed verbally by a lot of coaches, anyway) method is to drive the knee forward when you want to find some extra speed. They should "pump the arms, high knees!" because this is what is accepted as the method to find some more speed. So you push, rather than pull. The problem is (and what we need to consider) is whether this is actually done, or is it something that coaches shout out at athletes because that's what they SEE? In other words, is the instruction consistent with reality?

So which is right? What does 'common-sense' biomechanics say?

We now need to evaluate the merits of the arguments. As I said earlier, I do believe that the biomechanics of some aspects of these techniques (more on Chi in a moment) are sound, and the implementation of the technique is another story altogether, but let's look briefly at the biomechanics.

The fall and using gravity - taught or acquired?

According to the Pose website, Leonardo da Vinci once wrote that “Motion is created by the destruction of balance…” That means that if we wish to move forward, from a standing position, we have to remove the balance from the system (us). That can be done in many different ways. You can be pushed from behind, you can push off something, you can create force with the muscles to move forward (that is, jump), or, as the Pose method suggests, you can let gravity act on the system. This is done by leaning forward, until the force of gravity is sufficient to want to cause us to fall forward. That then, is the starting point for running.

The tricky bit is that once we're running, it's very difficult to see the system's balance. Movement, being dynamic, means that at any moment, balance (and forces) are changing all the time. Think of yourself sitting in a car - you're perfectly balanced while it moves, but if you suddenly slam on the brakes, you get shot forward, completely out of balance. Enter inertia, which is a big part of running. It makes sense that we would want to minimize the need for inertia to propel us forward! Instead, if we can remain in a constant state of motion through the force of gravity, it would theoretically provide an advantage.

So the logic is sound - it would make sense for an efficient runner to aim to keep their centre of mass as far forward as possible. The alternative is to lean backwards when running - that clearly doesn't make sense, and so leaning forward does.

Right now, you might be thinking "Hang on, that's obvious, how is that revolutionary and a new running technique?" To which my answer would be "Exactly, good point" Therein lies one of the first discussion points - is this lean something that should be taught, or is it done naturally? Is it revolutionary, or simply the packaging of good ideas, done anyway, into a new product? Think of when you run downhill - you tend to lean backwards because if you didn't, you'd fall face first down the mountain! That illustrates that we KNOW how to position our bodies in space. Not everyone gets this right, though. I've seen many runners who do have an excessive lean back, or they have a hunch in the shoulders that is also inefficient. These people are great candidates for some advice, a little change that will make the difference for that runner. It's up for debate though!

The landing - what do we do with our legs and feet?

The second issue with Pose is the landing. This is actually the most controversial issue and also the most misunderstood. The perception that has been created (willingly or not) is that Pose is forefoot running. If you read the description on the site, you'll notice the complete absence of reference to the forefoot. So I'm not entirely sure where this perception comes from. I suspect that it's a shortcut to explaining the technique, a way to instruct and inform people, but it's become the focus instead. People have written in and emailed talking about forefoot running, which is a little different compared to Pose and Chi. But to be honest, neither has done a great deal to overcome this perception, which has caused some problems, as we'll discuss tomorrow.

But returning to the technique, what happens is that if you are now leaning far enough forward, and then you pull your foot up underneath you, your NATURAL landing will be underneath your body as well. Try for a second to visualize what that looks like - a person stands, pulls their foot off the ground and then it lands again with the centre of mass having moved forward. The foot will land underneath the centre of mass. If you jump up and down in one spot, your landing point is below the centre of mass, and you land on the balls of your feet. It's almost impossible not to. But it's not the objective, it just happens. So that's where the perception comes from.

Speaking from a biomechanical point of view, it does make sense that the point of landing should be as close to the body as possible. If you land way in front of your body, then you effectively brake yourself. Think of a long jumper - they extend their legs in front of them for extra distance, and promptly come to a complete stop. So good running means you have to keep that distance between your landing point and your centre of mass as small as possible. Nothing false about that one, biomechanically speaking. Running is not a connected sequence of jumps, in otherwords - it should be fluid and linear, and that means as little pushing off and as little braking as possible.

The problem comes when you start to think about how the foot lands. It's probably impossible to run with a landing directly beneath your centre of mass. That would require you to be leaning so far forward, you'd probably be able to to touch the ground with your hand! So the limit to balance also limits the ability to get that landing directly underneath the hips (or wherever the centre of mass is). Also, if you chop your stride too much, then you start to compromise on the benefit of having longer legs - you effectively shorten your "reach". There is probably an optimal point on the 'curve' where you are both pulling up and extending your leg out. That remains to be measured though.

One thing that is certain is that the 'pendulum' style of running, which would suggest that you should try as much as possible to 'reach' out in front of you to lengthen your stride is bad. All that does is brake your natural movement every time you land. It's like running downhill and leaning far back - you will know that feeling of jarring every time you land.

What does the evidence suggest? If the Pose method is true, then one would expect that faster runners, who have apparently developed better running technique, would tend to be more mid-foot or fore-foot strikers, because they would be adopting the principles above. But studies actually show the OPPOSITE - in one study, 75% of elite runners (running at 3min/km in a 21km race) landed on the HEEL! That seems to suggest that heel striking is not necessarily bad. The 25% who were mid- or forefoot strikers were not necessarily the fastest runners, so it's not a case of run on your heels if you are slow and let the fast guys land forefoot!

So now we have a conundrum - the elite guys don't run like they're supposed to! Is it possible to run efficiently when landing on the heel? Not according to Pose or Chi, yet the best runners do - even Gebrselassie and Tergat, if you ever watch them land. When they sprint, they're on the ball of the foot, but not during the marathon. So that's an inconsistency, which we'll look at more tomorrow...

The implication of this is that perhaps this pre-occupation with how the foot lands is not good. Maybe it doesn't matter? There are far more serious implications of this forced forefoot landing though, which we'll look at tomorrow, but I firmly believe that the best is to let the foot land in a relaxed manner.


The problem is that as soon as you teach a runner the Pose (or Chi) method, you put an idea in their head that they must land midfoot or forefoot. Do you think it's easy for a runner to relax the foot, when all they think about is landing on a certain part of it? And that's the biggest problem with implementation - getting it right. Because getting it wrong has some pretty serious consequences. Read tomorrow for that post.

Pose and barefoot running - same biomechanics?

We received an interesting comment on the Kenyans, and the fact that they have the perfect running technique because they grow up running barefoot. I tend to agree, but would make the point, and this was something Nicholas Romanov (founder of Pose) used to say a lot, is that "not all Kenyans run Pose". Setting aside the fact that Kenyans have probably never heard of "Pose" and therefore couldn't run it (unless by accident!), it's an illustration of the fact that optimal running technique is very difficult to pin down. It also, very importantly, illustrates that there are athletes out there who run 'optimally', completely without any instruction. The question we should be asking is whether these runners are finding what works best for them, in which case, maybe those NOT running Pose have done the same? Why would some people stumble on a technique that is "optimal" and not others? Both are running 150km a week, pressurized to perform, doing the same training, with the same upbringing to the sport. Interesting concept...

How does Pose differ from Chi?

This is one that I'm probably not perfectly positioned to answer, relying only on what is available through the internet and the odd report I've read or discussion. But briefly, what the creators of Chi Running will say is that Pose differs from Chi substantially (they would have to say this, because otherwise they're selling the same thing!).

But rather than speculate, here is the answer, straight from the 'pen' of the founder of the Chi method, when asked about the difference between Pose and Chi. This was kindly sent to me by one of the readers, Clyde:

"ChiRunning and Pose share the same focus of leaning to engage the pull of gravity for propulsion. That is about the only similarity I can see.

"With the Pose Method, Dr. Romanov has runners land on their forefoot, while ChiRunning has runners land on their mid-foot. Landing on your forefoot requires your entire body to be momentarily supported by your calf, which, for long-distance runners, is more than that muscle was designed to do.

The Pose Method uses the leg more. With ChiRunning, we have the runners relax their lower legs as much as possible at all times in order to reduce work to the lower legs (which is one of the main areas where running injuries occur). We have runners lengthen their stride and increase their lean to run faster, versus picking up the speed of their stride. If your cadence picks up, as I think the Pose Method advises, it takes more leg muscle to turn your legs over faster. That's OK if you're a sprinter, and your race is over in 10 seconds. But ChiRunning teaches long-distance runners to rely more on your lean than your legs, and ultimately, it saves your legs."

So that's it in a nutshell. One point worth making is that Pose doesn't necessarily have runners landing on the forefoot, as discussed. It's happened, as I mentioned, perhaps because that's how it's been taught or explained. So it's true in that regard. But the second paragraph does pretty much say the same thing as Pose. In the Pose method, the cadence is increased because the legs have to keep up with the "fall" of the body, which, as I read it, is exactly the same as the method for Chi. So that's not actually a difference. I suspect that what is going on here, from both sides, is that they are trying to differentiate themselves by finding differences. Unfortunately, the only losers in this 'battle' are the consumers, or the runners who can't figure out what is different between them!

The other difference is the "holistic" positioning of Chi - it's name comes from the Tai Chi, and so there's a great deal more to it than simply running. I'm all for this, but to evaluate it scientifically is another kettle of fish altogether. Apart from those differences, I struggle to see the two techniques as being different - I think it's the same concept packaged under a different name. I'm sure advocates of both techniques will disagree, but it's hard to find key differences that are meaningful.

My feeling is that both techniques are taking sound biomechanics (which we've looked at and discussed) and packaging them in such a way that they become viable products. There are without doubt benefits to both, because as I've said, every runner can probably find areas to improve their running style or technique. But the real issue is whether we should be focusing on the principle, or the product? Because a pre-occupation with the product means that we are teaching people "how to run" and making radical changes to techniques that have existed for many years. If you are runner, having run one way for 20 years, you can imagine that changing EVERYTHING is really difficult. This practical limitation is one of the key reasons I'd advocate making subtle, smaller changes on a case by case basis, rather than courses. That said, there is little doubt that SOME people find success in these methods. Whether it's the product, or the principle that has created that success, is also debatble. Perhaps the same result was achievable through an educated eye giving small tips? The point is, the techniques are being taught in structured courses, to mass audiences, over weekends or afternoons. And that's the concept we need to evaluate!

One such course was held here in Cape Town, used for research purposes, and it generated some fascinating data, the only data on the techniques that I'm aware of. And because the athletes were monitored closely, we also have longer term outcomes for all of them. And that is the key here - does teaching the method actually make a better, more efficient, less injury-prone runner? Can runners be "taught" an entirely new method for running? Make no mistake, I firmly believe that runners can have their running technique improved - little changes here and there. But to apply a generic method in a coaching course, that's the acid test.

And in tomorrow's post, we'll look at what evidence there is that this works, and what the implications are for this technique training. Apologies for the long post today, but as one can see, there's a great deal to get through, and even this was only scratching the surface!

Ross

Breaking news: Haile Gebrselassie has just broken the world marathon record - 2:04:26.
Check out the splits and race analysis here.

10 Comments:

Anonymous said...

In my previous comment about Kenyan runners I failed to make a point: Do all elite Kenyan run the same way because they share common characteristics like: long slender legs, extremely low body weight and body fat, superb elasticity of the muscles? They all seem to share physical characteristics and style, is this just chance? Can we incorporate into our own meagre running some lessons (adapted to a heavier frame, etc)? For example I have never seen a Kenyan or any elite runner slump over, while many "regular" runners fail to run in an erect posture.

Keep up the good work!
George

Jonas said...

Although I am in no way a Chi running expert, and don't really run following the system, I just wanted to clarify something about running faster in Chi running.

In Chi running you always keep the same cadence when running, whether you're running slowly or quickly doesn't matter. What you change when you run quickly is your stride length, ie. how much you let your legs "kick" out behind you.

While it feels quite natural to increase your cadence when you quicken your pace (it is what people naturally do), it actually works to lengthen your strides by opening up your hip as advocated in Chi running. That said, keeping a constant cadence no matter if you're running uphill, downhill, or simply straight, is one of the hardest parts of the system (for me).

Ross Tucker and Jonathan Dugas said...

Hi Jonas

Thank you for your comments. Pose is the same in that regard - same cadence regardless of speed. Interestingly, this is not generally considered the most effective way to run, because the combination of cadence or length is what most consider the means to access more speed. Even Haile Gebrselassie, who the Pose advocates bizarrely say runs "Pose" uses both length and cadence to increase speed. The thing about this analogy, and using Haile G as a "poster boy for the technique" even though he's arguably never heard of it, is that it shows that Pose is nothing more than good running dressed up in marketing robes to sell...

But getting back to the discussion, I don't believe it's realistic for most back-of-the-pack runners, or even middle of the pack to only increase length, because the range of speeds being run is so high. In otherwords, most average runners will run 5:00 to 6:00/km on a slower day, and 4:00/km on a faster day. If that is the size of the difference, you cannot achieve it simply by increasing length. You have to increase cadence too. Once you're down below 4:00/km, it's another story, but still, I don't think it's efficient to only increase length.

Thanks for the comments!
ROss

stlouiscoach said...

You say above that "Pose is the same in that regard - same cadence regardless of speed". That is most certainly not true. I am a Pose certified running coach - I have attended training with the founder Nicholas Romanov and he most certainly (and me too) believes that your cadence gets faster as you run faster. What made you think what you said?

Ashish M said...

Where are these "studies" that show elite runners winning races while heel striking? Haile Gebrselassie and Paul Tergat most definitely are forefoot strikers - check it out for yourself on youtube.

Ross Tucker and Jonathan Dugas said...

Hi Ashish

The "studies" you ask about are published in peer-reviewed journals and the one I referred to in this post was published towards the end of last year in the Journal of Strength and Conditioning. I've been meaning to do a full post on this article, but have until now not been able to find the time. I will hopefully get this article up by tomorrow at the latest.

As for Youtube, you can't do science by watching a grainy video on YouTube. That really would be a "study" in the biggest sense. So by all means, formulate opinions based on the Youtube method, I'll stick to high speed cameras and confirmed footstrike patterns.

Just to add, it's entirely possible that they are landing midfoot (not forefoot). In particular, when Gebrselassie was a track runner, he was very definitely midfoot, but I don't believe that he lands forefoot during marathons. That's a function of running speed, more than anything. |But the study in question, which I'll summarize soon, showed that approximately 3 in 4 elite runners are heel strikers, and it's not a function of their position in a race. I'll get that article in as the next one!

Ross

Anonymous said...

Landing on the heels when running is not necessarily bad. what's bad is if you bare your weight on your heels.

Anonymous said...

This is true. The heel can brush the ground on the way to the body's "taking weight." The question is, "on what part of the foot does weighting occur." Even on YouTube, you can see that Gebrsellasie and Bekele are NOT weighting on the heel. It's either forefoot or midfoot.

Granted, depending on the video you can see them stepping ahead of their centers of mass, but they have not been attempting to learn with Pose methods of instruction and may train to intentionally step ahead at different time and in certain situations.

Anonymous said...

Pose and Chi are different:
1). Cadence -- In Pose, the cadence increases as you run faster, and the strides remain short. In Chi, the cadence remains constant, and you increase the strides behind your body when you run faster.
2). Trunk/Core -- In Pose, the trunk remains solid unmoved. In Chi, you continuously rotate pelvis with your leg movement.
3). Arms -- In Pose, arms are merely for a balance. In Chi, you swing arms to the rear to balance with the forward fall.

I used to have knee injured all the time. That's why I learned Chi (bought books, DVDs, metronome to keep the cadence constant, took group lessons & private lessons, and practiced 9 months). The result-- Badly injured ankles.

So I learned Pose (bought a book, watched all YouTube videos, read all articles on PoseTech web, and practiced 7 months). The result -- Unbearable ball of foot pain and toe injury.

I wish if I found your website before I spent so much time, money, pains and more doctor visits.

Simon said...

A great debate....but

Sorry to point out the obvious but what everyone has failed to see is the bigger picture.

We are not landing ball of foot (BOF) in Pose Running because of research. That's just there to support the blindingly obvious.

We landing BOF because we are designed to by evolution. Jump up and down on the spot. What part of the foot is best....BOF? Now lets make the impact and forces greater by moving forward. Should we change our landing. When barefoot we tend not too, so lets use nature as the easy answer.

This might seem to easy or obvious for alot of people but when we can train ourselves to land BOF in running we are training our calf and Achilles to load and unload properly (with less force than a forefoot runner). Some sensations of tightness and soreness in those areas are common because thats where we are landing and stabilising more frequently than before as a mid to heel striker! I would be VERY surprised to hear people feel it anywhere else! But with time our body adapts to this new movement.

Also Chi Running does NOT teach technique. They teach a descriptive form that has no scientific research to back it up (which is why it is interpreted differently by lots of people) and therefore is not a technique by definition.

The Pose Method is a technique and more. The Pose Method is about understanding and teaching movement, not just running. And when you look at the bigger picture, you will see we only move because of external forces and should ALWAYS oboe these (by coaching if you have to) in order not to go against our evolutionary bio-mechanics.

'I love science but sometimes it can be the best way to confuse what is already staring you in the face.'

www.dopose.com - finding your potential as a runner