Wed, 21 May 2008 08:51:02 -0400
http://www.technologyreview.com/Biotech/20806/?nlid=3D1087
Technology Review - Published by MIT
Wednesday, May 21, 2008
Amputee Gets a Shot at the Olympics
Hugh Herr explains the scientific evidence behind the decision.
By Brittany Sauser
Last week, Oscar Pistorius, a South African Paralympics runner, was granted=
the chance to fulfill his lifelong dream of competing in the Olympics by t=
he Court of Arbitration for Sports (CAS), in Lausanne, Switzerland. The cou=
rt upheld the appeal filed by Pistorius against the decision made on Januar=
y 14 by the International Association of Athletics Federations (IAAF) that =
banned the "blade runner" from competing against able-bodied athletes. The =
CAS ruled that the IAAF did not provide "sufficient evidence of any metabol=
ic advantage . . . [or sufficient evidence] that the biomechanical effects =
of using this particular prosthetic device gives Oscar Pistorius an advanta=
ge over other athletes not using the device."
Pistorius is a double amputee who competes on J-shaped, carbon-fiber, Cheet=
ah Flex-Foot prosthetics made by the Icelandic company =D6ssur. After Pisto=
rius performed well in an international able-bodied event in 2007, suspicio=
n arose among members of the IAAF that his Cheetah prosthetics may give him=
an unfair advantage. Immediately, the institution placed a ban on using "t=
echnical devices," such as wheels and springs, in competition, and it decid=
ed to individually review Pistorius's case.
The IAAF conducted a two-day scientific study, led by German professor Gert=
-Peter Br=FCggemann, of the prostheses. Based on the resulting data, the IA=
AF concluded that Pistorius indeed has an unfair advantage over able-bodied=
athletes, claiming that he uses 25 percent less energy than they do to com=
pete.
Astounded by such allegations, Pistorius's lawyers turned to MIT professor =
Hugh Herr and asked that he assess the scientific validity of the IAAF's st=
udy. Herr, the director of the Biomechatronics Group in the MIT Media Lab, =
and also an associate professor in the MIT-Harvard Division of Health Scien=
ces and Technology, assembled a team that included experts in biomechanics =
and physiology from six universities to evaluate the scientific evidence.
Technology Review sat down with Herr and asked him to explain the scientifi=
c flaws that the team of researchers found in the IAAF study, as well as th=
e broader implications of the CAS's ruling.
Technology Review: What were the claims made by the IAAF in its scientific =
report that you were tasked with assessing?
Hugh Herr: The first claim made by the IAAF was related to the metabolic en=
ergy required of Oscar to run. They claimed that Oscar, because of his Chee=
tah prostheses, was able to run at sprinting speeds with 25 percent less en=
ergy. In the second claim, the IAAF said the Cheetah prostheses release a g=
reater amount of energy than the human ankle-foot complex in sprint speeds,=
and that that, in fact, introduces an artificial advantage to Oscar.
TR: In regards to the first claim, how did the IAAF come to that conclusion=
, and what scientific evidence did you use to refute that claim?
HH: At sprinting speeds, the body uses two sources of energy: aerobic and a=
naerobic. The problem is that you can measure one energy source but not the=
other. Anaerobic energy cannot be quantified by anyone--not here in the U.=
S., not in Germany; it simply can't be precisely quantified. The IAAF claim=
ed that it could be quantified, and they put a precise number on it: 25 per=
cent energetic advantage at 400-meter-race speeds. This is deeply flawed be=
cause it can't be quantified at those speeds. No one can assess quantitativ=
ely whether there is an advantage or disadvantage.
TR: Then how did the IAAF quantify the anaerobic energy source in order to =
come to such a conclusion?
HH: They took blood lactate measures. But again, if one is schooled in the =
recent scientific understanding of anaerobic metabolism, one concludes that=
by simply taking blood lactate measures, one cannot quantify anaerobic cap=
acity.
At slower running speeds, the aerobic component can be measured by monitori=
ng how much oxygen a person consumes and how much carbon dioxide is release=
d. What we did is, we performed an energetic test at slower running speeds =
where one can quantitatively measure the total amount of energy required to=
run, because at that critical speed and below, the aerobic energy supply f=
orms the entirety of the energy source. We measured Oscar and other elite a=
thletes with intact legs at that speed and below, and we found no significa=
nt difference.
If the IAAF would have had their study peer-reviewed before deciding to ban=
Oscar, they would have found this out.
TR: In the second claim, the IAAF said that the Cheetah prosthetics returne=
d more energy than the human ankle-foot joint. How was that evaluated, and =
why do you believe the ruling is flawed?
HH: The IA
Long message truncated by MailBucket.