CT SI story on Oscar Pistorius

[Ken Jakalski]

Forum members will enjoy the following:

http://sportsillustrated.cnn.com/201...ics/index.html

[miaou]

Thanks, that was an interesting and surprisingly unbiased read. A couple of years ago, I did a short review on running/sprinting on prosthetics for a sports biomechanics class.

It is clear there is a disadvantage in the acceleration phase (no force production by the cheetahs, only elastic energy return, as opposed to an intact limb ankle, balances issues, etc.), but there are certain advantages in the max speed phase (greater energy return, lighter limb weights and COG's closer to the hips, etc.). It is really hard to explicitly quantify the advantages/disadvantages in a concise way (that would apply to all performances by all athletes wearing the particular prosthetics), and therefore compare them, and it would also depend on the different events (it is fairly certain the disadvantages would outweigh the advantages in the 100 m sprint, but it is nowhere as clear in longer events). My thoughts when reviewing the relevant literature were that, while it is hard to measure in strict quantifiable form, it is very likely that in the 400 m sprint the biomechanical (and ensuing metabolic) advantages do outweigh the disadvantages.

It is actually somewhat surprising that Pistorius hasn't made the switch from 400 to 800 meters, as there is every reason to except his prosthetics would offer a greater competitive advantage there. I wouldn't be entirely surprised if the reason he hasn't made the switch is that there might be a more obvious advantage if he competed in the latter event, which wouldn't be helpful for his quest to get accepted in able-bodied competition and the olympics.

Having said all that, the decision on whether he should be allowed to compete along-side able-bodied athletes is clearly a political and philosophical one, not a scientific one. It is clear that the cheetahs have specific advantages and, regardless of any disadvantages, that means able-bodied sprinters cannot compete with them on "equal grounds". On the other hand, nobody is born equal and nobody grows to be equal, people are born with different biomechanical/biological "specs" and enjoy vastly different environmental influences and, in the end, that is what determines who people are. If you chose to accept Pistorius' prosthetics as a part of who he is as a person, then sure, let him compete. If he wins over able-bodied sprinters because his prosthetics offer him specific advantages in particular events, well, then he wins over able-bodied sprinters because of who he is. Slippery slope, I know.

[Kyle Ridgeway]

Having said all that, the decision on whether he should be allowed to compete along-side able-bodied athletes is clearly a political and philosophical one, not a scientific one.

Excellent point, we could study and argue in circles for years about this topic. Politics aside, I would like to explore this issue from a philosophical perspective. Interesting and complex still, as you will have to construct or reference a philosophy of disability vs. ability. Is disability socially constructed or an unfortunate "condition" or a little of both?

What constitutes an unfair advantage? Or, excessive performance enhancement?

I think this scenario is fascinating, and on the whole glad he is competing.

[Ken Jakalski]

Legendary Giovanni Cavagna was one of the those responding to the controversy among the researchers in a JAP Point/Counterpoint

"At high running speeds, a large fraction of the power developed each step during the push appears to be sustained by elastic energy stored within muscle-tendon units during the brake. Elastic storage and recovery is improved at high speeds by privileging the role of tendon relative to muscle at the expense of a high muscle activation. Replacing muscle-tendon units with a passive, inexpensive, elastic structure may result in more efficient elastic rebound by increasing the power developed at low cost during the push.
At low running speeds, the step frequency f is advantageously tuned to the resonant frequency of the bouncing system fs . With increasing running speed, f increases less than fs to contain the power spent to reset the limbs at each step. If the half period of the bouncing system is measured in Fig. 1 of Weyand and Bundle , as the time where the vertical force exceeds body weight, the resonant frequency fs of the bouncing system results ∼60% greater than the step frequency f in the intact-limb subject and ∼30% greater in the amputee. If this is confirmed by measuring f and fs at different running speeds, the advantage of a reduced mass of the lower limb may be considered.
These two observations favor the hypothesis that artificial limbs may make artificially fast running speeds possible, even if, as stated by Kram et al., this hypothesis cannot be statistically proven."

[Ken Jakalski]

Hi Kyle!

What constitutes an unfair advantage? Or, excessive performance enhancement?

Excellent question!

I wrote to Matt Bundle today to tell him how much I appreciated his direct, unwavering response to Hugh Herr's view that researchers may never be able to quantify all the advantages and disadvantages--that it "may take years and years and it may not be knowaable."

"The technology is enabling him to do something that nobody else can do. that's the very definition of an advantage."

[Kyle Ridgeway]

"The technology is enabling him to do something that nobody else can do. that's the very definition of an advantage."

Others are more than welcome to have amputations and pursue this technology if they feel it to be that advantageous.

All kidding aside...Currently, I do not know why, but that statement seems just a bit unsettling to me. While factual accurate, I am not sure it appropriately captures the complexities of a situation where someone does not have legs, but through technology, training, and hours upon hours of practice achieves a mastery and skill that allows him to run at the highest competitive level, successfully.

He is not taking drugs and he didn't explicitly cheat per se. He is not on the far end of genotype or phenotype amazingness (although this point is open to debate).

He lives in this odd philosophical and conceptual space where he has taken a technologically adaptation, a necessary compensation given his physical impairments, and been able to produce a level of performance not otherwise expected.

May part of the issue lie in his actual performance? He is too good. No one with his physical situation should be able to perform at that high level unless the technology compensation gave him some distinct advantage?

These are questions I don't have answers to, of course.

[Kyle Ridgeway]

Pistorius "negative-split" the race in Rome, meaning that he ran the second 200 faster than the first, an unheard of strategy for elite quarter-milers. (Pistorius, though, no longer negative-splits his races.)

Read more: http://sportsillustrated.cnn.com/201...#ixzz22de7D4lW

Interesting quote. Your thoughts on that Ken? Indication of improved start/first split, or a conscious strategy??

[Diane]

In that he adapted to artificial legs from the age of 11 months, probably his only "advantage" is that he neuroplasticized/"incorporated" the legs early on, and (one presumes) had good control of postop pain/no phantom pain. I would think the younger one is (i.e., low weight) to have to adapt to art.legs, the better.
Plus it's easier for a tiny boy without life experience to consider himself "normal", especially if he is treated that way, which he was, so why would he know any different? .. than an adult who has to have both legs amputated because of, e.g., trauma.
I don't see how the blades provide advantage, especially since his weightbearing surfaces (tibias) have to endure unusual forces, so.. there is just that adaptation advantage he's had his whole life.

[Diane]

On the other hand, Michael Phelps supposed "problem", ADHD (2008), has never even been mentioned as maybe giving him an enormous advantage...

Instead, society judged him for self medicating, i.e., using something that presumably defocuses.

[Ken Jakalski]

Hi Kyle!!

He is not taking drugs and he didn't explicitly cheat per se. He is not on the far end of genotype or phenotype amazingness (although this point is open to debate).

My involvement with parlaympic sprinters goes back to '97 when then world paralympic sprint champion Tony Volptentest and single leg btk amputee Marlon Shirley competed on my high school track. Volptentest has neither feet nor lower arms. So I agree with you that what these athletes accomplish is truly amazing.

May part of the issue lie in his actual performance? He is too good. No one with his physical situation should be able to perform at that high level unless the technology compensation gave him some distinct advantage?

One of the arguments that Marlon Shirley and other single leg below the knee amputees raised is that double btk's like Pistorius have what is now referred to as an "unfair disability."

In other words, as a double amputee, Pistorius is able to manipulate the length of his prostheses. This is something single leg amputees like Shirley are not able to do.

These are questions I don't have answers to, of course.

Having spent some time at the Rice lab, I'm familiar with the protocols Drs. Weyand and Bundle used in their testing, and I know how determined they are to provide us with knowledge on the biomechanical means by which human athletes achieve faster speeds.

My only concern in all of this is good research being either dismissed or unfairly challenged because, as you so appropriately noted, "through technology, training, and hours upon hours of practice achieves a mastery and skill that allows him to run at the highest competitive level, successfully."

[John W]

I'm concerned that he's apparently using some calculation in order to compete at the highest level.

I wonder how people would react if he walked onto the track with prostheses that made him 8 feet tall? That "advantage" would at least appear obvious, so does he avoid this overt appearance of advantage as he's apparently done with no longer achieving his lower 2nd split time?

This is a tough one.

[keithp]

I had heard the therapist quoted here on NPR discussing the subject yesterday morning:

Dr. Robert Gailey is a University of Miami physical therapy professor and scientist who has worked with hundreds of amputee athletes and with Pistorius since he was a 17-year-old rugby-player-turned-sprinter using clunky old prosthetics. Gailey has been instrumental in Pistorius’ development and in his successful appeal of a ban by track’s governing body, the IAAF.

“He really has no advantage,” Gailey said. “He has a disadvantage. The major power generator for an able-bodied 400-meter runner is his ankles. Oscar doesn’t have ankles.”

Pistorius generates power from his hips, because he has lived his whole life that way. He is hindered at the start because he cannot jump from the blocks; he has to pull out. Able-bodied sprinters can keep their bodies low and wind resistant for the first 30meters. Pistorius pops up on his toes. In the turns, able-bodied athletes can drive off their outside foot. But Pistorius’ feet have no side-to-side motion. He has to keep his balance. Nor does he have a longer stride length, as the IAAF argued in a study that Gailey debunked.

Gailey’s research showed that able-bodied athletes get a 250 percent energy return when they’re sprinting compared with 80 percent for Pistorius.

Respectfully,
Keith

[miaou]

Gailey’s research showed that able-bodied athletes get a 250 percent energy return when they’re sprinting compared with 80 percent for Pistorius.

I am somewhat skeptical of these numbers. A "250 percent energy return" just doesn't happen at sprinting speeds, otherwise sprinters would never stop accelerating.

Looking through Gailey's published studies, as indexed by pubmed, these numbers don't appear anywhere (as a matter of fact, it appears that Gailey has no published research on sprinting, with prosthetics or otherwise).

These numbers are very similar to the ones reported by Czerniecky et al. (1991), who found that amputees using the Flex Foot (a prosthetic developed by the same company who later on produced the Cheetahs) got a 84% energy return, as opposed to able-bodied subjects with 241%. But this was for running speeds of 2.8 m/s; nowhere near close to sprinting speeds.

At slow running speeds, elastic energy storage is much lower and there is force production by the lower limbs. At these speeds, intact limbs will offer an energy return greater than 100% because of the force production of muscle contraction. But this is entirely different to what happens at top speeds, after the acceleration phase is over, where the energy return cannot possibly be over 100%.

In the Bruggemann study, where the speeds measured ranged from 9.2 - 9.5 m/s, Cheetah's energy return was found at 95%, and the authors concluded "the carbon keels provide a higher ratio of positive-to-negative work or a higher energy return than the healthy ankle joint while sprinting at maximum speed".

So, in fact, I'd consider the above quote to be somewhat misleading.

[Kyle Ridgeway]

One of the arguments that Marlon Shirley and other single leg below the knee amputees raised is that double btk's like Pistorius have what is now referred to as an "unfair disability."

In other words, as a double amputee, Pistorius is able to manipulate the length of his prostheses. This is something single leg amputees like Shirley are not able to do.

Comparing a double amputee to a single amputee, I would agree that it appears that a double amputee does have a tremendous advantage. I think using any single measure or investigation or investigators interpretation to illustrate that Pistorius does or does not have an advantage over a non-amputee is tenuous. Whether it's leg length, force production, fatigue factors, oxygen uptake, split times, time on the ground, energy storage/return, etc.

For the leg length issue, isn't it possible to predict the most anatomically accurate prostheses length to attain an accurate total leg length for each individual? In this case, leg lengths could be limited for each individual based on predicted anatomical leg length.

In that he adapted to artificial legs from the age of 11 months, probably his only "advantage" is that he neuroplasticized/"incorporated" the legs early on, and (one presumes) had good control of postop pain/no phantom pain. I would think the younger one is (i.e., low weight) to have to adapt to art.legs, the better.
Plus it's easier for a tiny boy without life experience to consider himself "normal", especially if he is treated that way, which he was, so why would he know any different? .. than an adult who has to have both legs amputated because of, e.g., trauma.
I don't see how the blades provide advantage, especially since his weightbearing surfaces (tibias) have to endure unusual forces, so.. there is just that adaptation advantage he's had his whole life.

Agreed, he developed and adapted to this unique situation while his nervous system was it's prime of development. This is in stark contrast to someone who has an amputation after physically and neurologically developing with two limbs.


A question on his original split times. Is it possible that he had a faster 2nd half split time, because his start (initially) was so inefficient, or his "weak spot?" And, over time he was able to improve his 1st half split time, because of an improvement in start/acceleration performance.

Regardless of our interpretation of the data regarding his relative disadvantage or advantage, philosophically what does everyone think regarding whether he should or should not be able to participate? Why?

[Diane]

Originally Posted by Kyle Ridgeway

Regardless of our interpretation of the data regarding his relative disadvantage or advantage, philosophically what does everyone think regarding whether he should or should not be able to participate? Why?

Is that question in the same league as "What does everyone think about whether women should or shouldn't be be allowed freedom to move about in society, have careers, earn a living etc? Why?"


Um, yes!!!!!.. because it's fair and just and right. Why or why not else?

[Kyle Ridgeway]

Um, yes!!!!!.. because it's fair and just and right. Why or why not else?

I agree! From some of the articles and debates happening, it appears that the public and media assume he has an unfair advantage purely because of his performance. And, thus are wary of him competing.

I am all for it, if for no other reason that it is so backwards to our normal conceptualization of disability, performance, and sport.

[Kyle Ridgeway]

Is that question in the same league as "What does everyone think about whether women should or shouldn't be be allowed freedom to move about in society, have careers, earn a living etc? Why?"

No, I don't think so.

[Diane]

I do.

[Ken Jakalski]

The following paper will help forum members get a better grasp of the findings that rasied all the controversy.

Journal of Applied Physiology April 1, 2010 vol. 108 no. 4 1011-1012

Title: Point: Artificial limbs do make artificially fast running speeds possible.

[miaou]

Originally Posted by Kyle Ridgeway

Regardless of our interpretation of the data regarding his relative disadvantage or advantage, philosophically what does everyone think regarding whether he should or should not be able to participate? Why?

My thoughts are it would depend on your understanding of athletic competition.

From a purely athletic performance standpoint, in terms of reaching the zenith of human body potential, he should not be competing simply because he competes on different grounds than able-bodied athletes and any comparison (which is what competition is about) is null.

From a more humanitarian standpoint, in terms of athletics as a form of signifying/celebrating human will and overcoming obstacles to make the best you can be as a person and inspire others, he should probably compete. Philosophically speaking, this may indeed be a slippery slope, but it is what it is.

For a sociological standpoint, where one of the primary factors deeming modern athletics meaningful is its marketing potential, Pistorius should obviously be allowed to compete as he is very marketable and ignites interest in the broad public.

Originally Posted by Diane

Is that question in the same league as "What does everyone think about whether women should or shouldn't be be allowed freedom to move about in society, have careers, earn a living etc? Why?"

Not at all.

[John W]

Originally Posted by Diane

Is that question in the same league as "What does everyone think about whether women should or shouldn't be be allowed freedom to move about in society, have careers, earn a living etc? Why?"


Um, yes!!!!!.. because it's fair and just and right. Why or why not else?

I don't see the parallel with gender equality issues here at all. The issue of fairness in this case has to do with performance on the highest competitive level, not the fundamental right to participate on an even footing (pardon the pun) in society in general.

In an interview I saw just yesterday by Mary Carillo with the developer of the Cheetahs, who happens to be a double amputee, he demonstrated running in place with some state-of-the-art prostheses with all kinds of electronic gizmos and sensors. This brief presentation was very impressive. Eventually, I imagine someone will be able to develop a set of these to tolerate the loads encountered in sprinting. Would that be fair to the runners who don't have "bionic" legs.

If there's notoriety and potential wealth to be gained, then it's just a matter of time before the technology produces a set of legs that perform better, on average, than natural legs, and this is precisely the Pandora's Box that is opened when you allow someone to compete with artificial limbs.

How about this: what if they found a way to dope the blood or use some lung bypass device in asthmatics to compensate for their lack of efficient oxygen transfer, which then would allow them to compete at the highest levels in racing events? Shouldn't people with asthma be allowed to compete at the highest level if medical technology could allow it? (For the sake of this example, make believe that current long-distance athletes don't already dope their blood. )

[Diane]

OK, how about "right to vote"?

[Ken Jakalski]

I recall that, back in '97, Tony Volptentest discussed the meaning of disability with us over dinner. He noted that, at one point individuals with poor vision might have been considerred disabled. However, glasses and eventually contact lenses corrected for that problem. And the corrections are so common that poor vision need no longer be considered a disability.

The questions raised here are good ones. At what point might technology go from being able to restore someone to some natural level of ability to providing what might be considered a "super-ability"?

We like to say that no medical technology can make someone "as good as new," but might in some areas of human performance could a technology advancement allow someone to perform "better than new"?

What John has touched upon--the Pandoras' box-- may be part of what's driving the Pistorius controversy.

As one reporter recently suggested--many of us belief that Pistorius is a wonderful story of man's triumph over an obvious disability, and we applaud his efforts--

"But what if he wins?"

[Diane]

Then he gets a medal. Right?

[John W]

Then he gets a medal. Right?

Well, that's not all he would get.

Endorsement Potential for Olympic Athletes

Note that the interviewee addresses what increased earning potential a spokesman with a "defining characteristic" might garner. I can't think of a more "defining characteristic" than having artificial limbs.

[Diane]

Ha. It would mean taking away the barrier of "other" that separates "normal" from "ab", "abled" from "disabled."

Seriously, barriers are still up everywhere. The ones excluding "women" from "human", therefore leaving us as "subhuman", are the ones that affect me the most. I am glad to have legs, of course. But am always pleased when social barriers vaporize into nothingness, once proven to have been bogus all the way along.

[Ref in Rehab]

First off, I have to admit to some bias on this one. One of my sons, now 12, was born with bilateral fibular hemimelia and (thank you Shriner's Hospital!!!) had his first surgery at 8 1/2 months, and walked with B BK prostheses at about 18 months. We've been following Oscar for some time in my family, and he's certainly an inspiration to my son.

I don't think this will be the last time that technology will have an effect on sport. Whether it's the rebound effect on baseball bats or golf balls, the size of the sweet spot on the face of a golf club, the hydrophobic suits that let swimmers go faster, etc. There is always a constant search for new technology to provide an advantage, whether an "external" advantage like Pistorius may have with his prostheses or an internal one via doping, improved training, etc. The governing bodies of sport will always be behind the curve a bit and then try to level the field.

[JayCola]

This is definitely situation that requires a very nuanced analysis. First off, there needs to be a general acceptance of what what constitutes fairness in sports and also what is the purpose of sport. As maiou pointed out, there will never be complete fairness given the inherent differences that come about in peoples lives (opportunity, good or bad fortune, access to wealth and education). As humans involved in competitive sports (and everything for that matter) we seem to ignore these factors in our discussion of fairness and success. Most importantly though, we accept the 'genetic lottery' each of us are given as being fair. 99.999% of the 7 billion people have lost this genetic lottery when it comes to being an Olympic athlete; they just dont' have the genes required to be physically (and mentally) capable of an elite level of athleticism.

There's no doubt Oscar was born in this 99.9%, the only difference is that his handicap is obviously apparent, and more easily relatable to other people who don't share it. I can more easily imagine what it's like to not have legs then not have the gene ACTN3. I think this allows for more of an emotional connection, and thus a bias in his favor compared to what other losers of the genetic lottery receive.

Another difference has to do with the biological and the artificial. I would argue one of the main purposes of competitive sports is to acknowledge and celebrate the peak of human performance. And obviously, this human performance should be based off biological factors (muscle strength, fatigue, respiration, ect). (granted these are value judgements and don't necessarily have to be this way, but given the historical and current views of sports, I'd say this is clearly the case).

So now the question becomes what steps can be taken to remedy someone's unfortunate luck in the genetic lottery? Given the strong stance taken against the use of performance enhancing drugs (which act biologically) it should be even more obvious that the use of performance enhancing prosthetics should also be banned. The issue should not just be whether there is an unfair advantage, the issue (given our definition of sport, competition and fairness) should be how far an individual can modify himself in order to compete against non-purposely (naturally) enhanced athletes (granted this whole argument hinges on our blind acceptance of the genetic lottery being fair, you may disagree, but that's how things are at the moment).

We are all 'disabled' is some respect, Oscar's disability is just more salient to his audience and sport-thankfully for him he has found a great way to compensate for it. It's just too bad that competitive sports isn't about compensating. (and this is coming from someone who is by far not a hard-nosed sports fanatic)

[nari]

We're are all 'disabled' is some respect, Oscar's disability is just more salient to his audience and sport-thankfully for him he has found a great way to compensate for it. It's just too bad that competitive sports isn't about compensating. (and this is coming from someone who is by far not a hard-nosed sports fanatic)

(my bold)

Well said, jaycola.

Nari

[Ken Jakalski]

Hi Sean!

I don't think this will be the last time that technology will have an effect on sport. Whether it's the rebound effect on baseball bats or golf balls, the size of the sweet spot on the face of a golf club, the hydrophobic suits that let swimmers go faster, etc. There is always a constant search for new technology to provide an advantage, whether an "external" advantage like Pistorius may have with his prostheses or an internal one via doping, improved training, etc. The governing bodies of sport will always be behind the curve a bit and then try to level the field.

Excellent point! The Pistorius story has divided public opinion just as it has dvided the scientists involved in his testing. Regardless, it has been a good story about overcoming obstacles, and such stories are always uplifting.

At the heart of the "but what if he wins" comment is the suggestion that the public outcry over the very issue you brought up would be far greater.

Just making his Olympic team is a wonderful story, and then advancing to the semis in his event makes this wonderful story even more amazing...but....were he to win against the world's best, the implications of his having an "unfair disadvantage" (or "cheating" to some) would go beyond casual discussion.

[ovpt]

"Excellent point! The Pistorius story has divided public opinion just as it has dvided the scientists involved in his testing. Regardless, it has been a good story about overcoming obstacles, and such stories are always uplifting.

At the heart of the "but what if he wins" comment is the suggestion that the public outcry over the very issue you brought up would be far greater.

Just making his Olympic team is a wonderful story, and then advancing to the semis in his event makes this wonderful story even more amazing...but....were he to win against the world's best, the implications of his having an "unfair disadvantage" (or "cheating" to some) would go beyond casual discussion."


if he had any chance of winning, i dont think he would have been allowed to compete. the outcry would not be from the public but also from the fellow athletes and the debate would have a chance of becoming negative toward Oscar and thus eliminating the feel good story that it is.

Technology is great and will be a part of sports but technology has to be a relatively even playing field such as external equipment rules that govern baseball bats, balls, etc. the question has to be more than '' what if he won?" because what if he won by a ridiculous amount due a new version of his prosthesis came out?

[Ref in Rehab]

Here's an interesting thought, especially amongst this crowd...

Say Pistorius was given a new set of Cheetah blades and was told they were "faster", does he run a better time because of his confidence? Do the other runners run poorly because they're more concerned about their opponents supposed advantage?

[Ken Jakalski]

Hi Sean!

Say Pistorius was given a new set of Cheetah blades and was told they were "faster", does he run a better time because of his confidence? Do the other runners run poorly because they're more concerned about their opponents supposed advantage?

This is interesting. Paralympian sprinters understand that a stiffer blade is more advantageous. That's what Marlon Shirley went to in an effort to beat Pistorius in the 100 a few years back.

The problem with a stiffer blade is the possibility of injury. This is what happened to Shirley. He was able to beat Pistorius in the 100, but suffered an injury in the process.

So, unless "faster" is no longer "stiffer," either a single or double below the knee amputee I think would be reluctant to bolt on new blades without practicing in them. In this case, he probably did work out in them, but if he actually raced in them, I wonder what his feel for those blades happened to be. I believe he would be able to tell whether there was something indeed "different" about the new blade's response, so I don't know if for him there might really be a "placebo" effect if the blade was not really different.

Regarding his competitors. Against able bodied athletes who had not competed against him in the past, I don't think they'd know what a change in blade might do for him--and against them.

However, among other paralypians, I think your point might be a factor, since those paralympians would have an idea what a more advanced blade might be able to do for a double btk amputee like Pistorius.

Good stuff!

[Diane]

I believe he would be able to tell whether there was something indeed "different" about the new blade's response, so I don't know if for him there might really be a "placebo" effect if the blade was not really different.

Yes, he would be able to instantly "know". He will have been through many pairs of leg shoes by now, in his life.