By Mike Rowbottom

Mike Rowbottom(12)As multiple Paralympic champion Oscar Pistorius, named in the South African team for the IAAF World Championships starting in Daegu later this month, prepares to race against able-bodied athletes for the first time in a championship setting, a fellow South African sports scientist is insisting, regretfully, that he should not be allowed to do so.

Dr Ross Tucker, a senior lecturer with the University of Cape Town's Exercise Science and Sports Medicine Department, has offered insidethegames a new analysis of the Court of Arbitration for Sport's (CAS) decision in May 2008 to allow Pistorius to compete against able-bodied runners, something he says was "a complete farce".

Tucker also feels that Pistorius, who runs on carbon fibre blades known as Cheetahs, is benefiting from technological advances similar to those in Formula One motor racing.

Based on tests performed by German professor Gert-Peter Brueggemann, the International Association of Athletics Federations (IAAF) banned Pistorius from competing against able-bodied athletes in January 2008. The decision was overturned fourth months later by CAS in May, based on evidence supplied by a group of biomechanics experts including Peter Weyand of Rice University and Hugh Herr of the Massachusetts Institute of Technology.

But Tucker, a qualified middle-distance coach who works with the Springbok sevens team as well as two Olympic kayakers, Shaun Rubenstein and Mike Arthur, maintains that, while there were flaws in the approach taken by Bruegemann, the study which effectively overturned it was also incorrect in its application.

"I think that both sides actually showed the same thing," he told insidethegames exclusively. "But the CAS hearing allowed the second lot of science to bull-doze the proper interpretation of the results. There is no way that they should have been allowed to make the conclusions they did."

Tucker also has grave concerns over the technological aspect of prosthetics which are now being manufactured.

"Any time you introduce technology that can make a bigger impact than a) natural ability or b) training, then in my opinion, it affects the integrity of competition and of performance," he said.

"I don't wish to watch Formula One where the engineers can tinker with equipment to find half a second, and that seems to me to be a possibility in this instance. Just to be clear, the companies that make these blades are innovating and developing prototypes all the time, and they're prototypes that have a potential performance advantage.

"Ironically enough, Pistorius' lead advocate scientist, Hugh Herr, who is himself a double amputee, is on record as saying that the day will come where prosthetic limbs surpass human limbs for performance.

"Weyand, who wrote the paper with the advantage, has said that this day has already passed. The point is that the technology is evolving, and the question is where does it end? So as soon as you introduce this 'unique technology' into competition, I think it's risky and I disagree with it."

Tucker insisted he had no ethical objections to amputees or double amputees competing with able-bodied competitors. "No, none whatsoever," he said. "The objection is towards the introduction of technology to 'level the playing field', when that technology may well skew the playing field dramatically.

"Unless you know that it's levelling, the introduction of this kind of technology introduces a variable to performance that is larger than the effect of training. When Pistorius goes away and improves by 1.5 seconds within a year, is that him, or is it a new prototype?

"When a carbon-fibre limb can be improved by two per cent, is that a real reflection of competition, or is it the athletic equivalent of Formula 1, where engineers do more for performance than the athlete? And this is not unrealistic. I know of Paralympic athletes who have been given prototypes to try out, call it a 'test drive' and they are instantly two seconds faster. Or they improve their long jump by a metre within a season. The technology leaps forward, and it's that that I have a problem with.

"From a scientific point of view, the only thing that will change in the future is that the advantage will increase in size, the disadvantage will decrease, and the net result will become more favourable.

"Until the science knows where this ends, I think it's very, very risky to allow him to compete. I think Roger Black put it best when he said that we don't know if he is an exceptional athlete or simply a good athlete with an advantage."

Oscar_Pistorius_with_scientistEighteen months after the CAS hearing, Weyand (pictured with Pistorius) published further research which appeared to reverse the initial study upon which he had been engaged, and maintained that Pistorius's carbon fibre blades gave him a 10-second advantage over 400 metres.

"I don't think he [Pistorius] should be running," Tucker said. "I think he gets an enormous advantage, and two of his own scientists who did the testing to clear him recently published a paper saying that he had a 10-second advantage.

"The media never picked up on this, but the short version is that the Court of Arbitration decision that cleared him was a complete farce, scientifically, as was the testing that got him off Only a year later, when the scientists had a split, did the 'truth' emerge."

After Bruegemann's study had shown that Pistorius used 25 per cent less oxygen than other sprinters during the 400m, the subsequent study found the figure to be 17 per cent. But Rice contends that that figure was decreased, firstly in comparison to distance runners, and then to elite distance runners, to the point where it was within admissible levels.

"It was, in my opinion, an amazing conclusion to reach," Tucker said. "And I appreciate the statistics of it, that they collected enough control data to conclude that he was 'statistically' similar. But that was because they added elite distance runners. So now we have a 400m sprinter, not even the best one who has ever lived, and his oxygen cost of running is LOWER than the lowest recorded human being ever."

Tucker, who is speaking at the ASICS UK Science Exercise and Medicine conference at London's ExCel in November, added: "Stats aside, what this means is that Oscar Pistorius is the most economical athlete, sprinter or distance runner, who has ever been measured. And that's despite running on a treadmill, at slow speeds, on blades that are especially designed for high speeds, and likely get more effective at those high speeds.

"Scientifically, I was astonished at that research, and in particular, the fact that it would be presented to the Courth of Arbitration without any kind of peer-review. Nobody saw it until those judges saw it."

Brueggeman's study, Tucker said, set out to show whether there was either a metabolic or a mechanical advantage to running on blades.

"The blades are significantly lighter than human limbs, and also are able to return significantly more energy than human tendon," he said. "The result is that the hypothesis would be that the energy cost of running would be reduced in Pistorius compared to able-bodied runners at the same speed. The counter-argument to this is that Pistorius has to use other muscles to compensate, and to balance, and so his energy use would be similar.

"What Bruggemann did [perhaps mistakenly] was to have Pistorius run a simulated 400m race while his oxygen use was measured. We do this because if you want to get an idea of energy use, you measure oxygen use. The problem is, when you are sprinting for 45 to 50 seconds, oxygen is only an INDIRECT measure of energy use, because your energy comes from two sources - oxygen and anaerobic sources. Therefore, measuring oxygen only allows you to measure part of the energy cost, indirectly.

"However, this is what he did and he found that Pistorius uses the same energy for the first few seconds of the 400m race, but the last 75 per cent of the race, Pistorius is using 25 per cent LESS oxygen than the able-bodied sprinters.

"That, in Brueggemann's view, was sufficient to conclude that he used less energy and may have a metabolic advantage. On the biomechanics side, Brueggemann did a lot of testing on the kinetics of running, the forces and so forth, and his ultimate conclusion was that the energy return of the carbon fibre blades (92 per cent) was far greater than the energy return from a human tendon, that Pistorius had horizontal braking forces half those of able-bodied runners and vertical forces 20 per cent lower.

"In all, he concluded that it was a 'bouncing locomotion#, not running, and may have been metabolically superior.

"The follow up testing challenged that metabolic conclusion. The main reason was that measuring oxygen gives only an indirect measure of energy cost, not a direct one, and this is because it is measured during sprinting.  So, what Weyand and Herr did is to put Pistorius on a treadmill, and measure him running and much slower speeds, when we can make more definitive measurements of energy and oxygen use.

"I have three major issues with this. First, Pistorius is running on blades that are specifically designed for sprinting, not jogging. So to measure him at slow speeds provides an untrue reflection of reality, because he is likely to be relatively WORSE at slow speeds - this is when his balance would be most affected.

"Secondly, putting him on a treadmill is equally likely to skew the result, because anyone who has ever run on a treadmill for the first time will tell you, it's not as easy in terms of balance as running outside. So here, you have this situation where a guy is running on sprint blades that are inherently unstable at slower speeds, and he is running at slow speeds on a treadmill.

"Nevertheless, they make the comparison, and what do they find?  First, they compare him to other sprinters at slower speeds. They find that he uses 17 per cent LESS oxygen even at slow speeds on a treadmill.

"This is pretty similar to what the German study found. Then they add some long distance runners to the comparison group.  Now the difference is almost se en per cent. Pistorius is using seven per cent less oxygen than distance runners. So then they dig about in the scientific literature, and they find studies of elite marathon runners, and they discover that Pistorius is now 3.7 per cent more economical than elite distance runners.

"Statistically, now, the addition of the elite distance runners has brought Pistorius' oxygen use back to within two Standard Deviations of the mean, and so statistically, they conclude that he is metabolically similar.

"So to repeat - he uses 25 per cent less oxygen than sprinters during 400m sprinter [the German study]. He uses 17 per cent less oxygen than sprinters at slow speeds, seven per cent less than distance runners, and almost four per cent less than elite distance runners who are not even tested in the same laboratory.  And this is the evidence which forms the basis for the paper in which they conclude that he is 'metabolically similar.'

"The Herr and Weyand study did do some other tests - there was a fatigue test to examine the rate of fatigue in Pistorius. The problem I have with this is the same problem that affects all studies like this, and that's that the rate of fatigue is very much dependent on pacing, and so I'm not convinced. However, even without this, the metabolic measurement would have been enough to me to say 'Hold on, something is not right here. We have a sprinter using less oxygen than an elite distance runner.'

"Then jump 18 months ahead. The CAS have made their decision, they've decided to back the second study, without peer review, and so Pistorius is free to run. Then comes the bombshell - two of Pistorius' own scientists, Weyand and Matthew Bundle, bring out a paper where they say that their data suggests a significant advantage. Weyand makes some calculations - which I think was disingenuous, because it tries to put a figure to the advantage - and estimates around 10 seconds in a 400m race.

"Look past the 10 second issue, and just consider what Weyand is saying. He is quoted in a number of statements at the time that they knew that the advantage existed as soon as they analysed the data 18 months ago.

"That is, they knew of the advantage while they stood before the CAS and said that there was no advantage according to the IAAF. And sure, the CAS defined a very narrow question and they were there purely to look at the science from Brueggemann. However, they are saying that they knew of the advantage, but said nothing about it.  Until 18 months later, which is really an amazing thing to say.

Oscar_Pistorius_showing_Cheetah_blades_March_2011"The basis for this third research article, incidentally, is that because Pistorius' limbs are so light, he is able to accelerate them so much faster than able-bodied runners. Weyand writes that he is 'literally off the biological charts'.

"The implication of having such high leg speed is that he spends more time in contact with the ground, which means he doesn't need to generate the same forces at the same speed, and so he has this advantage. The implication of the advantage, incidentally, is that he'll use less oxygen and energy to run, which confirms what was found earlier.

"The Weyand paper caused some debate - Hugh Herr argued against it and the argument got quite childish.  At one point, in a scientific journal, Herr quotes John McEnroe – 'You cannot be serious'.

"However, I saw nothing in Herr's arguments that suggests that Weyand's interpretation was anything but accurate.

"The only problem that Weyand did encounter was that he tried to estimate how large the advantage was, and worked it out at 10 seconds.  That was a mistake - it requires too many assumptions.  The reality is that the advantage couldn't be quantified the way Weyand tried it.  I understand why he did, and what he did, but it probably discredited his conclusion slightly.

"The issue never got completely resolved, of course, and the CAS don't review decisions, but I just found it extra-ordinary that this revelation of a large advantage could come from within Pistorius' own team, 18 months late, when they are saying that they knew it all along.

"As for what to make of the collection of evidence - there are three or four lines that suggest an advantage. There is Weyand's study on how fast he repositions his limbs. There is the oxygen cost of sprinting by the German study, for all its faults, and there is the Weyand/Herr study where he uses less oxygen than anyone ever recorded just about.

"Then there is the mechanics - more energy return, lower horizontal forces etc. The only piece that does NOT suggest an advantage is the fatigue profile, but all that suggests is that he fatigues normally. And as mentioned, I'm not convinced of that test given the ability to pace oneself.

"So my take - three out of three studies suggest advantage. It's just that the second of the three got through to the CAS without proper review, I think the conclusion they make cannot be defended by their data and their method, and to me, it only confirms what the IAAF found."

Asked what might convince him to allow Pistorius to compete at an Olympics, Tucker responded: "I'd like to see an analysis of how the sprint mechanics and energy cost of running would change if they increased the mass of the legs so that they are equal to a human limb and then let's see the impact it makes if his movements are 'normal' and what one would expect of a 400m sprinter.

"If that is the case, then even if the energy return is different, it may not be 'off the biological charts' as Weyand puts it, and it would create a more comparable situation, at least in terms of what we know about sprinting."

Mike Rowbottom, one of Britain's most talented sportswriters, has covered the last five Summer and four Winter Olympics for The Independent. Previously he has worked for the Daily Mail, The Times, The Observer, the Sunday Correspondent and The Guardian. He is now chief feature writer for insidethegames. Rowbottom's Twitter feed can be accessed here