On January 14, the IAAF issued a report revealing the results of scientific testing done on Oscar Pistorius. If you would like to be redirected to a summary of those results, click on the posts, below:
Leaked reports that Pistorius’ Carbon fibre prosthetic limbs provide a “considerable advantage”
The IAAF tests on Paralympic athlete Oscar Pistorius have now been handed to IAAF President Lamine Diack, and the early reports are that the tests have indeed confirmed that the carbon fibre prosthetic limbs, knowns as “Cheetahs”, do in fact provide Pistorius with “considerable advantage” over other runners.
Unfortunately and frustratingly for us, the IAAF have issued a press release which states that “the IAAF does not plan to discuss the contents of the report, or make any public announcement about any decision related to the report, until 10 January 2008″. Because of this, we don’t have access to the specific results and so we cannot, unfortunately, bring you any more detailed insights or interpretation of the specific test results. But the lead researcher, biomechanics expert Prof Gert-Pieter Bruggemann was quoted in a German newspaper as saying that the advantage is considerable – several percentage points in size. Apparently Prof Bruggemann was himself surprised at the size of the difference.
To be quite honest, I’m also surprised at the apparently definitive result, but not because I don’t think there is no advantage (I’m on record as suggesting about 5 seconds advantage, and only next year will the actual facts emerge), but rather because of my slight scepticism about the tests the IAAF eventually put him through. I think that the IAAF took on a brave, but essentially impossible question to answer by trying to find the mechanisms and underlying physiology for the potential advantage.
However, returning to the tests, the focus was clearly on the oxygen consumption and lactate accumulation during running. There was a very sound physiological basis for investigating oxygen consumption, but lactate was not quite as clear cut. There were also many potential pitfalls and possible problems with the measurement of these variables during a short duration sprint and sub-maximal exercise bout, so I’m not 100% convinced the issue is resolved – in my opinion, it has been for a while, but whether this result will end it, I’m not sure.
But because the test results are not available yet, it would pure speculation as to what they found. I suspect that his oxygen consumption must have been radically lower than other athletes’, but I would suspect even more strongly that the biomechanical assessment of the limbs (apart from the physiological data measured when he ran) were the clinchers in this argument.
The theoretical basis for an advantage
Now, it may seem radical to some of you that the prosthetic limbs actually provide an advantage. This is a case that has been absolutely gripping as far as sports science goes, and earlier this year, when we did a series on Pistorius and the possibility that he had an advantage, we tried to explain just what the basis of that advantage would be, and it produced some excellent debate and discussion (mostly, anyway!)
I think that in our 8 months of existence here at The Science of Sport, the longest post we ever did was one I wrote looking at all the available evidence and theories for Pistorius having an advantage. This was an epic post to write (and probably even more challenging to read!) so rather than rehash all the same old points, and put you through that test of endurance, I refer you onto the following post if you are interested in some of the relevant arguments:
The main point we were making in this post was that because the carbon fibre limbs are providing elastic energy return without any possibility for fatigue, Pistorius would have a substantial advantage that would be seen most in the second half of his races. The human tendon is also able to provide energy return, but it comes at a cost – this “cost”, while difficult to quantify, results in what we recognize as fatigue, with the athlete slowing down progressively as the race develops.
The Cheetahs, however, provide “free energy” the whole way around. In addition, the far lighter limbs (carbon fibre vs. bone, muscle, fat and blood = major weight difference) would also provide an advantage. There was a bit more to it than just this, but it’s covered in the above post for interested visitors. But basically, the hypothesis created based on this theory is that when everyone else was slowing down (despite the fact that they’re sprinting maximally), he would be speeding up.
With this hypothesis in mind, we waited for his first European race in Rome, and analysed his pacing strategy during that race. Sure enough, Oscar Pistorius ran a 400m race that no athlete has ever done – even the great Michael Johnsons and Jeremy Wariners were running a race completely different to Pistorius. We covered this analysis in the following post:
Now this finding alone could well have been enough to conclude that the advantage existed. In trying to find the mechanisms, the IAAF were really taking a chance, because mechanistic physiological studies are really very difficult to do. This one was particularly challenging, partly because of the fact that he is a sprinter (it’s far more tricky to interpret VO2 data in sprinting than long distance running), but also because of the emotional aspect of the issue.
An impossible question to answer
In fact, this is one of the most challenging scientific questions that I can think of, and if we had an award for “Stimulating science question of the year”, this would be it. The main issue is that the study is impossible to do “properly”. In other words, you cannot have a Control group, because you can’t have other athletes run on carbon fibre blades, and you cannot measure Pistorius running on normal limbs! So to actually ask the question “Do the blades give Pistorius an advantage over other runners RIGHT NOW?” is an impossible one to answer with 100% certainty.
And this is where many of the problems developed, because people, understandably, want this question answered. One has to realise that no one can answer this question, though.
Instead, the real issue was never whether this particular model of limb on this particular athlete provide an advantage. The real question that should have been asked is “Is Pistorius different from able-bodied athletes in a PREDICTABLE, measurable manner?” Because IF you can find difference, and IF you had predicted those differences based on the theory and physiology explaining them, then you would know that something was at play with the prosthetic limbs. And the extension of this difference, is that regardless of whether he’s better now, technological developments in the future would further improve the limb and eventually, this measured difference will become significant enough to see the athlete win. Now, the pacing data from Pistorius’ race in Rome was highly suggestive of this difference, and it was definitely a favourable difference.
The crucial point made in the earlier series was that if Pistorius went away and spent 2008 training and working with the engineers who make these blades, would he come back in 2009 running 2 seconds faster? If so, was it his hard training, or was it the technology? Ultimately, you’d never know, and for that reason, preventing the use of the carbon fibre blades was the correct way to go.
The IAAF – substantial investment and accommodation
The IAAF have been exceedingly gracious and accommodating in this case. They have bent over backwards, forwards, sideways, and done handstands in order to accommodate Pistorius on this issue, even paying for the tests to be done (a figure that would be in the high five figures, for the advanced type of testing that was done). Not that it is wasted funding, because the question was so fascinating and relevant, but because I don’t believe it was ever the responsibility of the governing body of the sport to prove the presence of an advantage, especially given that they have rules in place to regulate the equipment used by athletes.
Instead, I really do believe that it should have been up to the Pistorius team to prove that they did not have an advantage. That is, they were the ones requesting permission in a special case, so would have been well-advised to prove that the limbs were not advantageous themselves. Of course, the IAAF probably would have done their own testing, but had Pistorius and his team approached the IAAF with some data, their position would have been enormously strengthened.
One of the most telling indictments on the situation is that in 2005, I was called up by members of the Pistorius team who were looking for an “endorsement” that the limbs did not provide an advantage. I would not give that endorsement in the absence of test results and proof, and neither could Prof Tim Noakes, who I know was contacted as well. Both Tim Noakes and I advised them to get the scientific testing done before they even contemplated the bid to compete in Beijing. We both invited them to come down to meet with us in Cape Town and discuss the way forward, because it was quite clear that the science was the key and had to be negotiated eventually. Yet two years passed and nothing was done.
Now, the million dollar question – if it meant that much to you, and you were desperate to compete, and you KNEW that the scientific evidence was going to make or break your attempt, why would you not have had the testing done? So why not be proactive and make it even more difficult for the IAAF to prevent you from competing later on?
Instead, Pistorius and his team went on what the media called “PR and support generating tours” of the USA, drumming up support and funding for his effort – everything but the science. I was involved in a TV debate on the issue – the problem was that we never debated anything, because any science that was put forward was simply brushed aside and we were reminded that he is inspirational and a role-model. I agree on both points, but it definitely highlighted an aversion to proof, perhaps because that proof would should what that IAAF now have?
The focus on the support and PR was understandable though, I suspect most would do it, but it does highlight the difference in incentives between the groups. And ultimately, it was left to the IAAF to carry the can, and despite some debatable science tests, they carried the situation as well as I think anyone would ever expect.
What next for Pistorius?
As for Pistorius, there was a time earlier this year when the issue was topical and in the media every day, that he actually threatened at one point that if they banned him from running in the Olympics, he would quit the sport altogether and not even run at the Paralympics. This was an unfortunate comment, because he was effectively holding himself to ransom. Also, it didn’t demonstrate much respect for the Paralympic movement, and for the enormous role he could play as a role-model for people everywhere. Make no mistake, Pistorius is an inspirational character – it’s not for nothing that Tom Hanks has visions of a movie of his life! So I really do hope that he is able, assuming he accepts this decision, to move on and continue to inspire people with his determination and courage. The emotional issue should always be seen as distinct from the scientific one.
But for now, I feel the IAAF have made the right call – it’s taken a long time, and it may not even be finished yet! But based on the theory and the limited results so far, it’s a decision that is in the sport’s best interests.
We’ll do our best to bring you detailed reports and scientific interpretation as they come, if they come!