Amputate your legs and you'll run faster

[MasterOfMagic]

http://sportsillustrated.cnn.com/200...ics/index.html

Apparently the prosthetic legs they've come up with are more efficient than the real thing, according to one study, so they're not letting a double-amputee compete in the Olympics.

Its...kinda silly, don't ya think? :P If the study is right (which is debatable, I believe), I can see where they're coming from, but I 'unno. I still strikes me as funny.

[Professor Smarmiarty]

What's silly? That they don't let him run?
Clearly his leg attachments are performance enhancing. Cause he couldn't run without them.
And I saw them on the news back when he first applied. They look pretty efficient. All streamlined and stuff, unlike nobbly legs.

[MasterOfMagic]

Originally Posted by Barrel-Hating Sycophant

What's silly? That they don't let him run?

Well, the thread kinda ran away from me, but no. The silly thing is that you can run faster with your legs cut off. Anytime I see this story, all details are lost and I come upon that one idea.

Yeah, yeah, prosthetics and such. But still >.>;

[adamark]

I wouldn't let someone with one prosthetic run in the olympics, either.

Imagine if someone lost their hand in an accident and got a bionic claw. Quite an advantage for certain gymnastics that require a strong grip, wouldn't you say?

What if I lost half my brain and had a super computer installed in there, would it be fair to compete in trivia shows like Jeopardy?

The spirit of the olympics is pushing the human body to its limit. Someone like this *is* pushing their body, but it's relying a lot on the material of the prosthetics, too. If he made a world record in running, can we really say he is the fastest human runner, or that the artificial legs did it for him?

Same reason we don't allow steroid use, because it's not natural.

[Professor Smarmiarty]

Well I mean they were running tests to see if biomechanically he had to expend more or less effort to run. Ie how much gain he got from moving the bits of the legs he had compared to a normal athlete.
But if he was allowed it would open a ridiculous window. And it's impossible to calculate such things anyway.

[bluestarultor]

Actually, it's very possible. He's not only expending less energy on coordination and balance, what with not having knees, ankles, or toes to worry about, or any of the respective muscles controlling them, but there's also an easily measurable factor of energy absorption in his prosthetics. Obviously, since they're made out of some sort of fiberglass or plastic, it removes less energy from the system than flesh, neoprene inserts, and sole rubber. Plus, I saw a guy demonstrate how springy they were. Those things bounce like nobody's business. I'm not surprised they chose not to let him compete.

[Professor Smarmiarty]

Originally Posted by bluestarultor

Actually, it's very possible. He's not only expending less energy on coordination and balance, what with not having knees, ankles, or toes to worry about, or any of the respective muscles controlling them, but there's also an easily measurable factor of energy absorption in his prosthetics. Obviously, since they're made out of some sort of fiberglass or plastic, it removes less energy from the system than flesh, neoprene inserts, and sole rubber. Plus, I saw a guy demonstrate how springy they were. Those things bounce like nobody's business. I'm not surprised they chose not to let him compete.

But there are too many factors to fully calculate. You have to make a lot of assumptions. In this case the assumptions aren't case-breaking but in less extreme-cases it becomes more important.
It's a matter of precedent.

[bluestarultor]

Originally Posted by Barrel-Hating Sycophant

But there are too many factors to fully calculate. You have to make a lot of assumptions. In this case the assumptions aren't case-breaking but in less extreme-cases it becomes more important.
It's a matter of precedent.

The fact that they give him an essentially digitigrade gait should be enough. That kind of locomotion generally better lends itself to speed. The fact of the matter is that it's a difference of nearly a third.

Looking at the picture and some rough blocking, this is how it breaks down:




BHS, you're heavy into physics. It's pretty clear some of the mechanical advantages. They offer a single point of contact with the ground, negating heel-to-toe inefficiencies. Their curvature allows them to bend and spring back. The toe of the prosthetic is also beyond his leg, meaning that he has to walk with at least a slightly bent knee, and also giving him a greater span of gait in a run. In short, the guy benefits from these both in the lack of musculature to tire and the basic mechanics of digitigrade motion.

[Mesden]

His lack of ankles probably makes going around the curve an utter bitch, though.

[POS Industries]

Originally Posted by Mesden

His lack of ankles probably makes going around the curve an utter bitch, though.

I was about to argue something along the lines of him being a sprinter and not being sure if there are curves involved in the (insert number here)-meter dash, but then I remembered that you actually used to do this stuff and decided to defer to your judgment.

But yeah, as bad as it makes me feel, I don't think it would be right to allow him to compete against organic-legged runners, either. The legs he uses to run are mechanically very different from normal human legs and are designed specifically for faster performance. Despite this being what would otherwise be a handicap, it's a distinct advantage in this event that isn't available to the other sprinters.