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kirtley24
05-18-2008, 11:07 PM
Dear all,

Although I have no interest in sport, I confess to a certain prurient
interest in this controversy. It is, perhaps the most stimulating topic on
BIOMCH-L since Herman Woltring passed away. It really brings into the open
many gnawing discomforts that the biomechanics community have been living
with for many years.

I personally have a scientific curiosity and humanitarian desire to see
Pistorius compete with able-bodied Olympians (he is not the first,
incidentally - the amputee swimmer Du Toit, who uses no prosthesis but
qualified against able-bodied swimmers).

However, I also have a feeling that the prostheses are the thin end of the
wedge that began with Speedo swimsuits. It seems to me difficult to block
any future device or appliance once one is admitted. It is conceptually
similar to the use of drugs in sport.

The "scientific" evaluation seems to me nothing more than the philosophical
opinions of two camps: the Bruggemann-led purists (who I side with, but not
for the scientific reasons they put forward) versus the Herr-led
prosthetists. I really cannot see how this arguement can be settled by
scientific data - although like many of you I am immensely excited by the
debate!

Chris



On Sun, May 18, 2008 at 3:17 AM, Jamie S. Carruthers
wrote:

>
> Here are some of the previous statements regarding this topic:
>
> _http://au.news.yahoo.com/070717/2/13zgn.html_
> (http://au.news.yahoo.com/070717/2/13zgn.html)
>
> ""The prosthetic legs that double-amputee sprinter Oscar Pistorius
> races with provide less air resistance than normal legs, the IAAF has
> said.
>
> Davies said the initial research also showed that the way Pistorius
> distributed energy was virtually the opposite to able-bodied runners.
> And unlike able-bodied runners, Pistorius was faster at the end of
> the race instead of the beginning.
>
> Pistorius was able to run with his prosthetic blades at the same
> speed as the able-bodied sprinters with about 25 percent less energy
> expenditure," the report concluded.
>
> FURTHER TESTS
> The report said the returned energy from the prosthetic blades, known
> as "cheetahs", was close to three times higher than the ankle joint.
> "The mechanical advantage of the blade in relation to the healthy
> ankle joint of an able-bodied athlete is higher than 30 percent," it
> added.
>
> "It is evident that an athlete using the Cheetah prosthetic is able
> to run at the same speed as able bodied athletes with lower energy
> consumption."
>
> ========
> Yet in the recent media article from Rice University it states:
>
> ""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.
>
> 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.""
>
> ***Having seen Oscar compete it is obvious that during the second half of
> the race that he his faster than any other athlete.
>
> ================
>
> Professor Hugh Herr stated:
>
> _http://sports.espn.go.com/espnmag/story?id=3357051_
> (http://sports.espn.go.com/espnmag/story?id=3357051)
>
> A bilateral amputee professor named Hugh Herr works here (at MIT). If
> anyone
> can predict what sports will look like in 2050, it's Herr, who lost his
> legs
> 26 years ago in a climbing accident. Herr wears robotic limbs with
> motorized
> ankles and insists he doesn't want his human legs back because soon
> they'll
> be archaic. "People have always thought the human body is the ideal," he
> says. "It's not."
>
> =============================
>
> John Casler also noted:
>
> While I am not informed enough to have an opinion on the "equality" over
> all
> competitors, I might wonder or question the assertion of "metabolic"
> advantage.
>
> I, for over 20 years have used "stair climbing" as a great Cardio
> Stimulating activity, and regularly do so.
>
> During this period I have explored many climbing and descending
> experiments
> to compete with myself and become faster.
>
> It didn't take too long for me to find that climbing on my "toes" caused a
> greater blood flow to my calves. This then when viewed logically suggested
> several things:
>
> 1) The blood flow to the calves was significant.
> 2) The distance the blood was pumped was far greater from the heart, and
> surely offered greater stress
> 3) The circulatory efficiency of supplying blood both TO and FROM the
> calves
> was a greater stress due to the "Cul de Sac" system.
>
> In light of this, I adjusted my form to step deep into the step itself and
> land on the heel, reducing calf involvement. This then reduced blood
> requirement for the area. Additionally I pushed off with the heel, causing
> even greater hip and ham involvement.
>
> The proximity of the glutes and hams to the heart to both supply and
> return
> blood was far less stressful and my times steadily improved.
>
> Now while this certainly doesn't suggest that metabolic requirements are
> small, it does offer an interesting question as to if the shorter and more
> direct blood flow can offer metabolic advantage.
>
> While I might suggest it "does", I might also say that I can see no viable
> method of establishing the scope of the advantage, considering the
> disadvantages contained in the disability itself.
>
> =================
> Comments?
> Jamie Carruthers
> Wakefield, UK
>
>
>
>
>
>
> ---------------------------------------------------------------
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> ---------------------------------------------------------------
>



--
Dr. Chris Kirtley MB ChB, PhD
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