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Its a difficult one. A double amputee wants to run in the 'main' olympics. On the surface that sounds like a noble request that should be granted. On the other hand, his spring loaded artificial limbs means (if I recall coreectly) that he only as to expend 30% of the energy of an able bodied running to achieve the same. Unfortunatly, I agree he should be banned.
The next challenge with the development of this technology, what will become of the para-olympics? Will they become tests of ability or tests of the size of the bank balance to develop these 'blades'?
Thought I would include the following. Out of interest I Googled him for more information.
Born without the fibula in both legs and missing a number of other bones besides, Pistorius was 11 months old when his parents, Hende and Sheila, having consulted medical experts the world over, reluctantly signed the papers agreeing to have their young son's limbs amputated beneath the knee. "When people ask me what it's like having artificial legs I reply, 'I don't know. What's it like having real legs?' To all intents and purposes, I was born like this and it's all I know.
Fascinating stuff.
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:)
twirly
Mandy Brooks
Brooks Podiatry
S64 0DE
Suffering a fondness for odd things.
“ Though the mills of God grind slowly;
Yet they grind exceeding small;
Though with patience he stands waiting,
With exactness grinds he all. ”
- Pistorius was able to run with his prosthetic blades at the same speed as the able-bodied sprinters with about 25% less energy expenditure. As soon as a given speed is reached, running with the prosthetics needs less additional energy than running with natural limbs.
- Once the physiological potential of Oscar Pistorius and the able-bodied control athletes had been estimated, using three different methods, it is clear that Pistorius’ potential was not higher than that of the controls, even though their performance results were similar.
- The biomechanical analysis demonstrated major differences in the sprint mechanics used by a below-knee amputee using prosthetics when compared to athletes with natural legs. The maximum vertical ground reaction forces and the vertical impulses are different in a highly significant way and the amount of energy return of the prosthetic blade have never been reported for a human muscle driven ankle joint in sprint running.
- The positive work, or returned energy, from the prosthetic blade is close to three times higher than with the human ankle joint in maximum sprinting.
- The energy loss in the prosthetic blade was measured at 9.3% during the stance phase while the average energy loss in the ankle joint of the able bodied control athletes was measured at 41.4%. This means that the mechanical advantage of the blade in relation to the healthy ankle joint of an able bodied athlete is higher than 30%.
If having blades gives this young man such an advantage where are all his record breaking times?
He is an amazing athlete given his situation, but what the studies (and IAAF) are saying is that physiologically he is a good athlete, with an advantage- this brings him close to the level of an olympic qualifier. If someone who was at an olympic level with natural legs had these blades instead, then the records would come (or so they say).
This would be more likely over the 400m where maintaining maximum velocity for a long period of time is the key. He is not very fast off the mark (relatively), but maintains a high velocity and is relatively faster over the second 200m. Supposedly this is due to the fact that he has to do 'less work' and does not fatigue like full limbed athletes.
Pretty amazing guy however way you look at it though!
__________________
Craig Tanner
Podiatrist ASPETAR-
Qatar Orthopaedic and Sports Medicine Hospital
Doha
QATAR http://www.aspetar.com/
It was only a matter of time before the challenge of Oscar Pistorius would run headlong into our cherished notions of what's equal, what's fair and what's the difference between the two.
Quote:
A runner's stride is not perfectly efficient. Ankles waste energy—much more, it turns out, than Pistorius' J-shaped blades. He can run just as fast using less oxygen than his competitors (one describes the sound Pistorius makes as like being chased by a giant pair of scissors). On Jan. 14, following the findings of the researcher who evaluated him, the IAAF disqualified Pistorius from Olympic competition. He is expected to appeal, arguing that the science of advantage is not that simple. Tom Hanks is interested in his life story. No matter what happens next, Pistorius is changing the nature of the games we play.
Sports Illustrated are reporting: Amputee runner wins right to try for Olympic spot
Quote:
Double-amputee sprinter Oscar Pistorius won his appeal Friday and can compete for a place in the Beijing Olympics.
The Court of Arbitration for Sport ruled that the 21-year-old South African is eligible to race against able-bodied athletes, overturning a ban imposed by the International Association of Athletics Federations.
CAS said the unanimous ruling goes into effect immediately.
Pistorius still must reach a qualifying time to run in the individual 400 meters at the Aug. 8-24 Beijing Games. However, he can be picked for the South African relay squad without qualifying.
Pistorius appealed to CAS, world sport's highest tribunal, to overturn a Jan. 14 ruling by the IAAF that banned him from competing. The IAAF said his carbon fiber blades give him a mechanical advantage.
A two-day hearing was held before a panel of three arbitrators at CAS headquarters last month.
Pistorius holds the 400-meter Paralympic world record of 46.56 seconds, but that time is outside the Olympic qualifying standard of 45.55. His training has been disrupted by the appeal process.
Even if Pistorius fails to get the qualifying time, South African selectors could add the University of Pretoria student to the Olympic 1,600-meter relay squad.
Pistorius would not require a qualifying time and could be taken to Beijing as an alternate. Six runners can be picked for the relay squad. Pistorius also expects to compete in Beijing at the Sept. 6-17 Paralympic Games.
The verdict also clears Pistorius to dedicate himself to competing at the 2012 London Olympics.
The IAAF based its January decision on studies by German professor Gert-Peter Brueggemann, who said the J-shaped "Cheetah" blades were energy efficient.
Pistorius' lawyers countered with independent tests conducted by a team led by MIT professor Hugh M. Herr that claimed to show he doesn't gain any advantage over able-bodied runners ...
It is interesting that as everyone starts fading at the last straight he is still powering on.
The line must be drawn some where, if he was allowed to run in the Olympics this year it would only mean the Olympics would be won by the "6 million dollar man" in 2012, Go Steve Austin !
Lets see what funky designs of "shoes" the able bodied start wearing now...
I just thought, with a pair of blades attached to my legs I'd stand at about 8 feet tall- My teenage dream of breaking the high jump world record may come true after all.
Here is a very good summary of the situation from ScienceDaily: Study Revives Olympic Prospects For Amputee Sprinter
Quote:
Based on Rice and MIT findings, the Court of Arbitration for Sports in Lausanne, Switzerland, has ruled that Pistorius is eligible to participate in International Association of Athletics Federations sanctioned competitions. If he qualifies for the 2008 Beijing games, Pistorius would be the first disabled athlete ever to run against able-bodied athletes in an Olympic event.
A world-renowned team of experts in biomechanics and physiology from six universities, led by Professor Hugh Herr of the Massachusetts Institute of Technology's Media Lab, refute scientific claims that the prostheses worn by Oscar Pistorius, a 21-year-old South African bilateral amputee track athlete, provide him with an unfair advantage in the 400-meter race. Their conclusions were based on data collected at the Rice University Locomotion Laboratory, under the direction of Professor Peter Weyand. Pistorius hopes to run in the 400-meter race at the Beijing Olympics this summer.
Based on the team's findings, the Court of Arbitration for Sport (CAS) in Lausanne, Switzerland, has ruled that Pistorius is eligible to participate in International Association of Athletics Federations (IAAF) sanctioned competitions. If he qualifies for the 2008 Beijing games, Pistorius would be the first disabled athlete ever to run against able-bodied athletes in an Olympic event.
The team's findings were presented to the CAS April 29-30 by Herr and Professor Rodger Kram of the University of Colorado at Boulder, and provided the foundation for Pistorius' appeal to overturn the IAAF decision that previously banned him from running against able-bodied athletes in races that are governed by IAAF rules. The team's findings were presented at the CAS, where Pistorius was represented by the international law firm of Dewey & LeBoeuf on a pro-bono basis.
In addition to Herr, Weyand and Kram, the panel of experts included Professor Matthew Bundle from the University of Wyoming, an expert in the energetics and mechanics of sprinting performance; Craig McGowan, from the University of Texas at Austin, a leading authority on muscle, tendon and joint mechanics;
Alena Grabowski, from the Massachusetts Institute of Technology, an expert in human locomotor energetics and biomechanics; and Jean-Benoît Morin from the University of Saint-Etienne, an expert in the mechanics of human running performance.
None received compensation for their research or participation in the hearing. The authors plan to submit the study to a peer-reviewed journal now that the legal case has been settled.
The scientific team was asked to evaluate the IAAF's initial claim that the Cheetah Flex-Foot prostheses (J-shaped, high-performance prostheses used for running) worn by Pistorius give him an advantage over able-bodied runners. The team concluded that the scientific evidence put forth by the IAAF investigation to ban Pistorius was fundamentally flawed. "While an athlete's performance in sprints of very short duration is determined almost entirely by mechanical factors, in races of longer duration, such as the 400m, performance depends on both mechanical and metabolic factors," said Herr, a bilateral amputee who heads the MIT Media Lab's Biomechatronics research group.
Based on this performance link, the scientists refuted the IAAF findings on two major points: the speed-duration relationship and rates of metabolic energy expenditure.
Specifically, the scientists concluded that:
* Pistorius' ability to maintain speed over the course of longer sprints--his speed-duration relationship--is essentially identical to that of able-bodied runners, indicating that he fatigues in the same manner as able-bodied sprinters.
* Pistorius' rates of metabolic energy expenditure do not differ from elite non-amputee runners. In particular, he has nearly the same running economy, or rate of oxygen consumption at submaximal speeds, and a similar maximal rate of oxygen consumption as elite non-amputee runners.
"Based on the data collected at Rice, the blades do not confer an enhanced ability to hold speed over a 400m race," Weyand said. "Nor does our research support the IAAF's claims of how the blades provide some sort of mechanical advantage for sprinting."
"The study commissioned by the IAAF claimed that Pistorius has a 25 percent energetic advantage at 400m race speeds. That claim is specious because anaerobic energy supply cannot be quantified," Kram said.
In summary, the team of experts unanimously concluded that the IAAF allegations were not scientifically valid.
I've had several debates with guys at my track club recently regarding pistorius. With most of us predominantly running from 200 --> 800m, we figured the main limiting factor at our level in 400m running was the lactic in the last 80 --> 120m, this man's limiting factor is not that part of the race! It seems he clearly runs -ve splits every time he runs, perhaps 24/22.5? Also, I don't know too many runners who have been in the sport for less than 4 years who can suddenly run 46's?
Without arguing the case of Pistorius and whether he should/should not be in the Olympics with able bodied runners, his advantage over able bodied runners is that he doesn't have to worry about stress #s, tenosynovitis, compartment syndromes etc. that elite runners worry about.
Without arguing the case of Pistorius and whether he should/should not be in the Olympics with able bodied runners, his advantage over able bodied runners is that he doesn't have to worry about stress #s, tenosynovitis, compartment syndromes etc. that elite runners worry about.
Just a point!
But think disadvantages of it..... For a start, no proprioreception from the feet. The extra stress that the rest of his body is put under in order to run on the prosthetic feet..... All the force is point loaded through the Patella Tendons and the residual muscles are having to work much harder to enable the prosthetic limbs to function. And ALL amputees will get skin breakdown on the stump sooner or later... especially if they are as active as he is!
I believe that anyone who wants to run in the Olympics is definitely at a disadvantage if they have bilateral transtibial amputations!!!
Its a difficult one. A double amputee wants to run in the 'main' olympics. On the surface that sounds like a noble request that should be granted. On the other hand, his spring loaded artificial limbs means (if I recall coreectly) that he only as to expend 30% of the energy of an able bodied running to achieve the same. Unfortunatly, I agree he should be banned.
The next challenge with the development of this technology, what will become of the para-olympics? Will they become tests of ability or tests of the size of the bank balance to develop these 'blades'?
hmmm... you are correct with your last statement. There are loads of Prosthetic feet out there made by many different companies. Prosthetic feet are like trainers in many ways, every athlete is sponsored by different companies (in Pistorius' case Ossur) and each company's foot will do the same basic job in a slightly different way (like Nike or Reebok running spikes do); to make everyone use the same foot would make it fairer, but would also Monopolize the paralympics!
The recent competitive successes of a bilateral, transtibial amputee sprint runner who races with modern running prostheses has triggered an international controversy regarding the relative function provided by his artificial limbs. Here, we conducted three tests of functional similarity between this amputee sprinter and competitive male runners with intact limbs: the metabolic cost of running, sprinting endurance, and running mechanics. Metabolic and mechanical data, respectively, were acquired via indirect calorimetry and ground reaction force measurement during constant-speed, level treadmill running. First, we found that the mean gross metabolic cost of transport of our amputee sprint subject (174.9 ml O2 kg(-1) km(-1); speeds: 2.5 to 4.1 m s(-1)) was only 3.8% lower than mean values for intact-limb elite distance runners and 6.7% lower than for sub-elite distance runners, but 17% lower than for intact-limb 400-meter specialists (210.6 [13.2; SD] ml O2 kg(-1) km(-1)). Second, the speeds our amputee sprinter maintained for six all-out, constant-speed trials to failure (speeds: 6.6-10.8 m s(-1); durations: 2-90 s) were within 2.2 [0.6]% of those predicted for intact-limb sprinters. Third, at sprinting speeds of 8.0, 9.0 and 10.0 m s(-1), our amputee subject had longer foot-ground contact times (+14.7 [4.2]%), shorter aerial (-26.4 [9.9]%) and swing times (-15.2 [6.9]%), and lower stance-averaged vertical forces (-19.3 [3.1]%) than intact-limb sprinters (top speeds = 10.8 vs.10.8 [0.6] m s(-1)). We conclude that running on modern, lower-limb sprinting prostheses appears to be physiologically similar, but mechanically different than running with intact limbs
MRC researcher A/Prof Tim Bach was featured on the ABC's science program Catalyst for the olympics special edition in July 2008. The program featured a story on the use of "blades" prostheses, which can be viewed for free here:
Running-specific prostheses (RSP) emulate the spring-like behaviour of biological limbs during human running, but little research has examined the mechanical means by which amputees achieve top speeds. To better understand the biomechanical effects of RSP during sprinting, we measured ground reaction forces (GRF) and stride kinematics of elite unilateral trans-tibial amputee sprinters across a range of speeds including top speed. Unilateral amputees are ideal subjects because each amputee's affected leg (AL) can be compared with their unaffected leg (UL). We found that stance average vertical GRF were approximately 9 per cent less for the AL compared with the UL across a range of speeds including top speed (p < 0.0001). In contrast, leg swing times were not significantly different between legs at any speed (p = 0.32). Additionally, AL and UL leg swing times were similar to those reported for non-amputee sprinters. We infer that RSP impair force generation and thus probably limit top speed. Some elite unilateral trans-tibial amputee sprinters appear to have learned or trained to compensate for AL force impairment by swinging both legs rapidly
Science Daily have this story on the above research:
Notion That Amputee Runners Gain Advantage From Protheses Further Disputed
Quote:
A study by six researchers, including a University of Colorado at Boulder associate professor and his former doctoral student, shows that amputees who use running-specific prosthetic legs have no performance advantage over counterparts who use their biological legs.
A debate on the matter was spurred when Oscar Pistorius, a bilateral amputee, was barred from the 400-meter dash at the 2008 Olympic Games in Beijing, and other able-body races. The International Association of Athletics Federations that barred Pistorius claimed his Cheetah Flex-Foot prostheses provided significant advantages over non-amputee competitors, agreeing with other studies that found prostheses reduce the energy cost of running. In addition, some have proposed that the lighter weight of specially designed sport prostheses facilitates a quicker swing of the leg.
The new study was published Nov. 4 in Biology Letters, a journal of the Royal Society in London, and is co-authored by Alena Grabowski and Hugh Herr of the Massachusetts Institute of Technology, Craig McGowan of the University of Texas at Austin, William McDermott of The Orthopedic Specialty Hospital in Murray, Utah, and Rodger Kram of CU-Boulder's department of integrative physiology and its Locomotion Laboratory. Grabowski, lead author on the study, received her doctoral degree in integrative physiology at CU-Boulder under Kram in 2007.....
Science Daily are reporting: Oscar Pistorius' Artificial Limbs Give Him Clear, Major Advantage for Sprint Running, New Study Suggests
Quote:
ScienceDaily (Nov. 17, 2009) — The artificial lower limbs of double-amputee Olympic hopeful Oscar Pistorius give him a clear and major advantage over his competition, taking 10 seconds or more off what his 400-meter race time would be if his prosthesis behaved like intact limbs.
That's the conclusion -- released to the public for the first time -- of human performance experts Peter Weyand of Southern Methodist University in Dallas and Matthew Bundle of the University of Wyoming.
The Weyand-Bundle conclusion is part of a written Point-Counterpoint style debate published online in the Journal of Applied Physiology on Nov. 19.
Weyand and Bundle were the first two authors of the study publishing the test results acquired as part of the legal appeal process undertaken after the governing body of Track and Field -- the International Association of Athletics Federations (IAAF) -- banned Pistorius from able-bodied track competitions, including the Olympics....
Science Daily are reporting: Oscar Pistorius' Artificial Limbs Give Him Clear, Major Advantage for Sprint Running, New Study SuggestsFull story
Thank you!! Finally, after reading the rest of the biomechanical analyses earlier in this thread which did not consider the forward recovery phase energetics of running with reduced mass artificial limbs.......now comes some common sense biomechanics/physiology that takes into account the dramatic effects that reduced limb weight has on the work and energy involved during the forward recovery (i.e. swing) phase of running for someone running without the normal distribution of mass at the end of their running limb. No foot......reduced mass at end of limb....reduced moment of inertia of limb....increased angular acceleration of limb during forward recovery.....faster "recovery" time of limb. Case closed.
Lesson learned.....just because people are called "experts" by others.....doesn't mean they are right.
__________________
Sincerely,
Kevin
**************************************************
Kevin A. Kirby, DPM
Adjunct Associate Professor
Department of Applied Biomechanics
California School of Podiatric Medicine at Samuel Merritt College
Seeing as other I'd like to suggest that perhaps it's not the hardware after all, but their determination? And, that Oscars' real advantage is this -
(watch that bilateral whip btwn 0.25 ~ 0.26 btw!).
Seeing as other I'd like to suggest that perhaps it's not the hardware after all, but their determination? And, that Oscars' real advantage is this - .
Most competitive athletes have great determination. However, even the best, most-determined runners don't have the short duration of forward recovery phase that Oscar uniquely has in his running gait cycle. This short forward recovery phase occurs due to his low mass "legs", not his "determination".
Sure, I give Oscar lots of credit....but his success is partially due to his light weight prosthesis.....and not only due to his determination.....and his product endorsements.
__________________
Sincerely,
Kevin
**************************************************
Kevin A. Kirby, DPM
Adjunct Associate Professor
Department of Applied Biomechanics
California School of Podiatric Medicine at Samuel Merritt College
We found that stance average vertical GRF were approximately 9 per cent less for the affected leg (AL) compared with the unaffected leg (UL) across a range of speeds including top speed (p < 0.0001). In contrast, leg swing times were not significantly different between legs at any speed (p = 0.32). Additionally, AL and UL leg swing times were similar to those reported for non-amputee sprinters. We infer that RSP impair force generation and thus probably limit top speed. Some elite unilateral trans-tibial amputee sprinters appear to have learned or trained to compensate for AL force impairment by swinging both legs rapidly.
Also, if the RSP's were such an advantage then one would ask: why aren't there a significant number of amputee runners achieving as well as Pistorius?
I would suggest that it's a combination of -
* determination - they need to out perform non-amputee athletes for obvious reasons
and
* technique - as the paper above suggests, but also because they have to cope with a higher centre of gravity, socket/skin interface issues, lack of proprioception, potentially abnormal alignment (see the bilateral whip above) and, in some cases, abnormal joints.
Amputee Pistorius makes world champs
Milan
July 20, 2011 - 8:34AM
Oscar Pistorius qualifies for the track and field world championships for the first time, with a personal best in the 400 meters of 45.07 seconds, in Lignano, Italy.
South African double amputee Oscar "Blade Runner" Pistorius has qualified for the athletics world championships next month and could be on his way to the 2012 Olympics in London.
Pistorius clocked a personal best of 45.07 seconds at a 400-metre race in Lignano, Italy, surpassing the time of 45.25 he needed to qualify for the South African team to compete at the world championships in Daegu, South Korea.
Pistorius gained international fame when he tried to qualify for the 2008 Olympics and had to battle a ban by world governing body the IAAF from competing in able-bodied races after his carbon-fibre blades were deemed an unfair advantage.
He went to the Court of Arbitration for Sport and was cleared in 2008 but the legal process took a toll on training and he didn't come close to the qualifying time for Beijing.
Blade runner (Oscar Pistorius)
And, that Oscars' real advantage is this - 
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