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kirtley24
05-21-2007, 12:06 AM
Dear all,

I wonder if I might raise a related question?

These days transfemoral prostheses are so good that we may have reached the
point where it may be worth considering amputation in cases where the foot
is severely deformed or non-functional, e.g. as a result of neurological
disorders (stroke, cerebral palsy etc.) or even such conditions as
rheumatoid arthritis.

Yet I have rarely heard this option raised with a patient - I wonder why?

Chris


On 5/20/07, Joe Laszlo wrote:
>
> Hi all,
>
> I only lurk on biomech-l periodically, but this topic and subsequent
> discussion really caught my attention.
>
> I'll prefix by saying I would *love* to see Oscar run in the Olympics
> and hate to say anything to discourage it. I think it *should*
> happen, but not as part of the current 100m event. Instead, it should
> be a separate 100m event class: the first(?) fully-peered "disabled"
> event in the Olympics proper (vs. the Paralympic games). To me, this
> seems to address many problems, both technical and political. It's
> also a possible initial step on a path to (eventual)
> Olympic-Paralympic integration IF that's desirable (I personally think
> so, but it's not my opinion that matters). More below.
>
>
> First, a few thoughts I *think* haven't been directly noted (fully, in
> any case). My apologies if they have and I've missed them; I've tried
> to read & catch up on the many good responses diligently. A great
> topic and lots of fantastic points, BTW -- well done, all (especially
> Ton, for helping "instigate" [in a positive sense!] so well :-)
>
> In particular, I love the points re "purity of sport" and the "Olympic
> principles of inclusion and inspiration". We are, after all, talking
> about the Olympics.
>
> ---
> The thoughts:
>
> Reduced weight and some other potential mechanical advantages of
> runners like Oscar have been noted. The weight/moment factor alone,
> noted by Joel Perry (maybe others as well?), seems huge to me, even if
> current prostheses aren't yet able to fully exploit it, but I *think*
> two factors haven't been highlighted fully:
> 1. potential advantages during training, as well as competition;
> and
> 2. energy/equivalence arguments *may* not be relevant, even if proven
> "fair"
>
> Joel also pointed out the issue of "able-bodied" athletes body parts
> surviving the high stress of near-maximal performance. IMO it's worth
> noting that this also applies to training. *Potential* hamstring,
> achilles or other injuries seem to be ever-present factors, maybe even
> limiting factors, in training, at times. Prosthetics users will have
> different potential injury factors, but any "fair equivalence" is
> unclear. Steroids and other related substances enable higher training
> loads and are banned, for example (not to say that they are directly
> comparable!).
>
> Athletes using prostheses (note that I did NOT say disabled!) may have
> significant advantage here both in training and competitive
> performance (as well as disadvantages). Could external (or one day
> even internal or hybrid) synthetic fibre functional "tendons" or
> "ligaments" help mitigate weakest-link injuries allowing higher
> performance? Synthetic joints? (& combinations thereof?) I think a key
> point is that IF these would be disallowed for a competing field of
> "able-bodied" athletes, allowing it for "disabled" athletes competing
> directly with able-bodied athletes seems unfair. Similar prostheses
> adapted to able-bodied runners would be illegal (according to the
> noted "shoes with springs" rule) and as far as I know is untested, but
> so-called "power stilts" are a current, clear, if more crude, example.
> These are passive fibreglass-spring stilts which enable much higher
> leaping heights and running speeds than unassisted. I don't know if
> shoes which only extend the leg would be legal -- it seems hard to
> argue that they wouldn't have explicit "springs" of some form. On the
> other hand, could the soles of any sprint shoes currently in
> competition use be considered spring-like (from the contact area)?
>
> So far a primary goal of prostheses has been to restore or match
> equivalent function as much as possible. This seems mainly because we
> just haven't really been quite as good as nature... yet. Make the
> function very specific and we can probably already surpass it in some
> cases. This _will_ become more general.
>
> For an athelete with part of the lower leg(s) missing, we are
> effectively replacing part of the body with an artificial functional
> unit. Eventually this will be able to exploit potential advantages.
> Consider a mechanism that optimally varies effective leg length, to
> reduce the moment of the return leg, say passively, for the sake of
> argument -- is it still "fair"? Extend to above-knee amputees
> (eventually). There's even an argument that this could potentially be
> _electronically_ controlled (& thus much "smarter") in a "technically
> fair", but probably not "fair in spirit", way -- if the power came
> from the athlete's at-the-time motion. I'm not even certain if that's
> still purely "future work", but it's surely not *too* far off.
> There's a lot of kinetic energy in a sprint to play with trading off a
> small percentage of it well, maybe even for "able-bodied" runners
> (e.g. with some form of online "bio-cues" for optimal performance?).
>
> Regarding an upper-body amputee sprinter competing, personally, I
> think that's fine with no prostheses, but that upper-body prostheses
> could have similar (but probably reduced) advantages.
>
> Regarding energy-equivalence arguments, different events can have
> equivalent energy or power requirements but should "clearly" still be
> separate events -- in a sense, this is the very basis of most event
> classifications. A swimming vs. running sprint is a somewhat
> ridiculous example, to make the point. The distinction between
> "traditional" and "skating" techniques in cross-country skiing events
> in the winter Olympics is a more compelling example. This takes away
> nothing, of course, from the great discussion on how best to do this
> evaluation if it's considered salient.
>
>
> I think it's, unfortunately, too *potentially* unfair to allow direct
> head-to-head in this way, however inspirational and inclusive it may
> be, especially when you consider that the Olympics and IOC are
> inherently "long term" in outlook. Whatever you choose to call it,
> it's effectively just too *different*. Different, not [dis]abled.
>
> ---
> Which leads nicely to my proposed solution:
>
> 1. Have (add) a separate double-amputee class 100m sprint event in the
> Olympics-proper.
>
> 2. IF there is effective consensus that Paralympic and Olympic events
> should (eventually) be integrated: remove the event *from* the
> Paralympic games - the first full step in the transition, regardless
> of how long it will take.
> Note: this is a purely political issue I'd rather support competitive
> athletes' preference on. I'm not one myself, so I include it as part
> of the greater "golden opportunity" I'm suggesting technical
> justification (and some political opportunity) for.
>
> 3. Do it for 2008. Great potential benefits are there now; deferring
> it risks being too late.
>
> 4. Promote it like crazy, hopefully making pretty much everybody happy
> (win-win-win-win :-).
>
>
> IOC and/or related governing bodies: if you do it for 2008, give
> yourself a very well-earned pat on the back. Really.
>
>
> I think doing this would maintain whichever form(s) of the "Olympic
> spirit" you prefer, addresses many hairy political issues quite well,
> and may even help pave the way to meaningful
> "assistive-whatever-you-like" competition down the road ("able-bodied"
> or not -- make the distinctions fairly categorical, not
> "[dis]ability"-based!).
>
>
> ---
> Some thoughts on political and "Olympic principles" issues, since I
> feel they do relate both back, to technical issues, and ahead, to
> future biomech-related research and technology development:
>
> Foregoing direct head-to-head competition, could be viewed as a
> "concession", but I think that the strong symbolic gesture & direction
> alone could do and mean _much_ more for *all* so-called "disabled"
> athletes, going forward, than any few individuals competing
> head-to-head in any particular, probably questionably fair, and
> politically fraught event. IMO, the proposed solution offers:
> 1. The first-ever (I think) official Olympic event for so-called
> "disabled" athletes; one which may have the potential to actually
> exceed unassisted human performance;
> 2. A (potential) clear path to eventual integration of the Paralympic
> and Olympic games, on a piece-wise, "as appropriate" basis; if
> desirable, this may be much a more likely path than doing it en-masse
> - and what better event to first do this with than the current marquee
> event of the Olympics? (!)
> 3. On a more distant time horizon: a potential path (again, if
> desired) to evaluate and advise competitive consideration of various
> "biomechanically assistive performance technologies" that will surely
> come along, as we push human performance limits. Who would be
> surprised if future athletic disciplines of *public* interest involve
> increasingly tightly integrated technology and surpass unassisted
> human abilities? This is surely of *eventual* Olympic interest, even
> if it is resisted initially. This opens the door to testing those in
> a way that will hopefully be of wider general benefit.
>
> That most or all competitors (in the new 2008 double-amputee 100m
> sprint) will probably perform well below the typical levels of the
> marquee event doesn't matter. The top sprinters of some countries far
> under-perform those that don't even make the national team in others.
> That's the Olympic inclusion principle - everybody gets to compete if
> they meet the standards bar _in the appropriate designated event(s)_.
> The cross-country skiing styles is an example again. The clap-skate
> is another which was also handled differently, but may even one day
> spawn a "traditional" event(?).
>
> Regarding inspiration, what about when (if) a "disabled" athlete one
> day shatters the human-propelled speed record? At some point, the
> tables may even be exactly reversed, and the entire field of the 100m
> assisted/amputee (and/or maybe the assisted/non-amputee?) race(s) will
> blow away the top "unassisted" 100m sprinter and become the hallmark
> event of the games. *That* would be landmark, but that's what I'd bet
> on. I can't wait! ("Disability, schmisability!" :-)
>
> In the meantime, the Olympics would be taking a positive, proactive
> direction and essentially bypass some of the political quagmire that
> the spectre of head-to-head competition raises, in a way that would
> hopefully lead to wide-spread (higher/faster/stronger) technological
> benefits for everyday real people with disabilities & related
> challenges. The main exception, politically, being the issue of
> whether to begin "splitting off" Paralympic events.
>
> In fact, even head-to-head is still possible, outside the Olympics, or
> in an "open" 100m event, perhaps better left to a future point,
> if/when enough assisted-device sprinters approach and might surpass
> unassisted Olympic competitive performance levels. That could be
> quite a spectacular draw during the "transition period", if it ever
> happens.
>
>
> One thing I do hope is that IF there's strong consensus in principle
> among the athletes for eventual integration of Olympic and Paralympic
> events, and if the propsed approach seems sound, that all hands pull
> together to help make it happen. The logistics alone, of shooting for
> 2008, will be challenging enough, and if "assistive device" runners do
> eventually outpace unassisted runners, it *may* be a much more thorny
> issue for 2012, with the "transition" possibly already even well
> underway.
>
>
> My $.02 (perhaps $.04), for what it's worth. Sorry if I've gone a
> little overboard with the length and any rhetoric; the topic got me
> positively fired up. :-)
> Please feel free to criticize as appropriate.
>
> Also, while I don't ever recall seeing or hearing such a suggestion
> previously, if it pre-exists, please note it & advise me to attribute
> credit appropriately(!)
>
> Cheers! (& thanks again for the great discussion!)
> Joe.
>
> --
> ------------------------------------------------------------
> Joe Laszlo
> jflaszlo@cs.toronto.edu
> Ph.D. Candidate, Dept. of CS
> Dynamic Graphics Project
> University of Toronto
> [ but I speak only for myself, of course ]
> ------------------------------------------------------------
>
>
> On 5/18/07, BIOMCH-L automatic digest system
> wrote:
> > There are 12 messages totalling 1182 lines in this issue.
> >
> > Topics of the day:
> >
> > 1. Biomechanics of the Lower LImb - Early Bird Registration
> > 2. Last Minute Reminder - 2007 Injury Biomechanics Symposium
> > 3.
> > 4. amputee sprinter (7)
> > 5. Quantifying Spasticity Using Isokinetic Dynamometry
> > 6. PhD Positions at the University of Southampton, United Kingdom
> >
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>



--
Dr. Chris Kirtley MB ChB, PhD
from 1 May to 31 July 2007 I am at:
Stiftung Orthopädische Universitätsklinik Heidelberg
Leiter Ganganalyselabor
Anschrift: Schlierbacher Landstr. 200a
69118 Heidelberg

Tel: 49+06221-96 6724
Fax: 49+06221-96 6725

Clinical Gait Analysis: http://www.univie.ac.at/cga
Book:
http://www.amazon.co.uk/exec/obidos/ASIN/0443100098/203-6674734-4427132