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Thursday, June 25, 2009

Pistorius research published

Research on Oscar Pistorius, the human kangaroo is finally published

After many months of waiting, and about one year too late to be deemed scientifically credible, the research on the "Blade Runner" has finally been published. Amazingly, the title of the research is: The fastest runner on artificial legs: different limbs, similar function?.

This is amazing because the study finds, among other things, that Pistorius uses 17% less oxygen than elite 400m runners. Incredibly, he also uses LESS oxygen (3.8% less, to be exact) than elite distance runners! Given that this is at sub-maximal speeds, where the differences are likely smaller anyway, it is absolutely extra-ordinary that he used this in his defence.

Further, the study concludes that running on the prostheses is "mechanically different from running on intact limbs" and that Pistorius is "physiologically similar" even though the metabolic costs are 17% lower - that's not similar, Dear scientists. Again, extra-ordinary "science"...and what is even more amazing is that this is the scientific evidence that somehow got him cleared to compete by the CAS. That, unfortunately, is the consequence of allowing legal experts to make a judgement on a scientific matter.

The background and the prospect of some interesting discussion

Those who follow this site, and have followed the argument, will know the development of this story, and you'll know my opinion on it. I have no doubt at all that he receives an advantage from the use of the high-tech, carbon fibre blades that he uses to run on. In October 2007, the IAAF commissioned research in Germany that showed this, and he was banned.

His response was to find scientists in the USA who would support his claim, and Professor Hugh Herr of MIT obliged by doing a study that formed the basis for Pistorius' defence, which was taken to the Court of Arbitration for Sport in Lausanne, where he was cleared.

Unfortunately, the scientific process, where research is peer-reviewed and evaluated was never followed. And so whereas Pistorius got to view the IAAF research and spend two months preparing a case, the same was never true for Pistorius' claims. His research was presented on one single morning, and a judgement was delivered by a panel that was frankly incapable of evaluating the scientific argument.

At the time, everyone was left speculating as to the nature of this "research" (the quotation marks are used for a reason there). The CAS hearing revealed little, other than that Pistorius has punched holes in the IAAF findings (which was not difficult to do - welcome to science), and that legally, he was cleared.

I heard from various journalists who had insight into the testing and the findings, and frankly, it was appalling what was being reported - systematic selection of control subjects so that Pistorius would look more similar to them than was the case, for example. That was rumour, but now there are facts, thanks to the publication of the research in JAP.

The research shows some extra-ordinary differences - how did they win the argument?

And it's just as appalling, mystifying and extra-ordinary that he got away with it. To borrow the words of Amby Burfoot over at Peak Performance at RunnersWorld.com, "frankly, we don't see how they won the argument. Pistorious apparently uses 17 percent less energy than similar 400-meter specialists, and runs with a stride that is "mechanically different than running with intact limbs.""

I'm going to have a detailed look at that paper, and try to summarize the implications of the findings over the course of the next few days. Having started with this story back in 2006, the next step needs to be taken, and this paper in a scientific journal is that next step.

To end off, a quote from the paper, just to set the scene:

"We conclude that running on modern, lower-limb sprinting prostheses appears to be physiologically similar (My comment: This is not true - his metabolic cost is 17% lower), but mechanically different than running with intact limbs"

Join us in the week, when I'll unpack the findings in more detail. All findings will lead to the same point - Pistorius does not "run" as we know running, and there is no reason to doubt the theoretical basis for an advantage, and the CAS bunged the decision.

Ross

7 Comments:

Jot said...

Thought you might be interested in listening to a fairly long interview with him.

http://www.competitorradio.com/details.php?show=310

-Jot

Andrew said...

Any thoughts on how/why the CAS believed the arguments of Pistorius but not those of Tyler Hamilton or Floyd Landis? I realize the potential for political influence, but I'm wondering how the three cases compare on a scientific basis. In my non-sports-scientist mind, Hamilton and Landis seemed to have far stronger cases than Pistorius did.

Duff said...

Their method, and therefore their conclusion, are flawed. They are
asking the wrong question to begin with.
Their Method
You cannot make a fair comparison between a group of runners with intact legs and a group of runners with prosthetic legs when the group of runners with prosthetic legs consists of only 1 runner. A sample size of 1 is not nearly large enough to be representative of the population of all runners with prosthetic legs. Any conclusions based on such a small sample size have no statistical significance and should be tossed out the window. Also, suppose someone has the genetic gifts to potentially run a 2:05 marathon, but that person has no interest in running. Then suppose that person lost his legs and got a set of prosthetic legs, and then decided to train like an elite marathoner for several years, and found that his best marathon time was 2:15, which is not 2:05, but it's still an elite time. You could not then correctly conclude that he had an advantage simply because he ran an elite time, because in fact,
he would have run a faster time if he had intact legs, all else being
equal. Therefore, the question should not be "Do prosthetic legs give a runner an advantage over runners with intact legs?" The question should be "Do prosthetic legs give a runner an advantage over himself if he had intact legs instead?" I doubt that anyone will ever find the answer to either question.
my 2 cents anyway

flashpeter said...

In my opinion he uses less oxygen just because he doesn't have to supply the muscles he doesn't have. The work normally done by muscles is replaced with mechanical response of his prostheses.

Grant said...

Here here flashpeter.
The more muscle that is employed the higher the matabolic cost.
If it gives him such an advantage (and a so-called 17% advantage is HUGE in athletic terms) then why is he not thrashing all-comers and setting new world records?
Give the guy a break and think of it from his point of view - who else can he compete against at his pace? Not much fun beating people by several seconds in a 400m race.

Michael Mc said...

Sure, and why not allow the wheelchair athletes compete as well? It is either a significant mechanical advantage or it isn't. "Giving someone a break" because we're sympathetic and he isn't quite talented enough to destroy the world record isn't the right approach. With such a marked advantage at some point a stellar athlete will come along and make this as ridiculous as the wheelchair suggestion.

Ross Tucker and Jonathan Dugas said...

HI all

To respond.

First, to Andrew. I don't know the specific details of the science behind the Landis and Hamilton case, because all I've ever seen about them are what has been reported in the media. They certainly did seem a little more robust than this research. This research was done with a very specific purpose, and the scientists just added runners until they found enough evidence that Pistorius was "not different". That these were distance runners was beyond the point. For Landis and Hamilton, I guess their cases revolved around proving scientific misconduct/error on the part of the testing authorities, which is a little different to this, where the facts were being debated. Unfortunately, "facts" are hard to come by.

To Duff

Yes, you're absolutely right. Problem is, you can never do that study, but you are still stuck with this situation, so you have to figure out how to best answer the question. I agree that it's flawed, but the IAAF research carried the same flaw. It would be great to do the perfect study though. My criticism of this study is more the way they did it - compared OP to THREE 400m runners, and the rest are all distance runners. And they still conclude that he is similar to other runners with respects to fatigue and VO2 max. It's a crazy comparison. but that is what their agenda called for.

Then to flashpeter and Grant.

yes, of course the reduced O2 cost is down to the reduced muscle mass. but then that's precisely the point. He is getting energy return without cost. You and I don't enjoy that - we get out less than we put in (so does OP), but the key is that we have to invest to get return, he doesn't. If you refer back to all the other articles I've written on this subject, then you'll see the scientific debate on the theory, and then maybe realise why your position is not quite as simple as it sounds.

And finally, to Grant, you can't just let him run because he wins his own division. this is not nursery school.

And as for the issue about him beating other runners because of his huge advantage...you're assumption is completely flawed because you're assuming he is a naturally gifted athlete to begin with. I am not sure how good an athlete you are, but I'd hazard a guess that if I gave you a 30% advantage, you'd still struggle to compete with elite 400m runners. I know I would. So your position is incorrect from the outset - there's no guarantee of victory just because an advantage exists.

Then to Michael, in principle, correct. While it would be pretty easy to see why wheelchairs should be banned, it does raise the point that you can’t just open the sport up, because someday, we might be in for a surprise when a better, or more disciplined athlete comes along and suddenly we’re saying “We’ve messed this up here”. So I agree, sympathy is not grounds for allowing anyone to run. There are thousands of people just as worthy, for whom the sport represents a way out of a way of life. Let them all run. Sport doesn’t work that way, I’m afraid.

Ross