equivalence or augmentation?


The August 8 issue of Sports Illustrated includes an article titled, “Prosthetics: Between Man and Machine.” In that piece, one of the leading voices on the future of prosthetic technology, Hugh Herr (a bilateral amputee himself), is quoted as follows:

“[Prosthetic technologies of the future will] be so exciting that regular old arms and legs will seem dull,” Herr says. “If the Paralympics accept advances in technology, there’ll come a time when the Paralympics will be more popular than the Olympics. There’ll be these insane human-machine events.”

Herr continues:

“In the future there’ll be a class of transportation devices in which limbs are augmented,” says Herr. “And if you’re an amputee born today, there’s a good chance that, in your 20s or 30s, your athletic performance will be augmented [beyond that of a nonamputee] and your daily life at least normalized.”

I don’t doubt the ability of Herr and others like him to eventually deliver some version of this reality. But there’s a bigger issue here that I’ve discussed previously: is an era of prosthetic augmentation what the limb loss/disability community wants or needs?

1. the world of prosthetic equivalence

Both people with LL/D and those without would, I think, agree with the following principle: if you lose/are born without your limb(s), you should have the right to technology that allows you to replace what’s not there. Indeed, most Americans reflexively think that if they lost a limb today or were born without it, their insurance would provide them a replacement. (Most Americans are wrong, but that’s a discussion for another day.)

If you dug a little deeper and asked the question, “What does it mean to replace what’s not there?”, you’d end up with a similarly consistent response: “It means getting a replacement limb that functions as well as a regular limb.” Or, stated another way, every person with LL/D has a fundamental right to a prosthesis that allows them to do everything an able-bodied person does the same way an able-bodied person does it. If such technology existed today, you would have what I call the World of Prosthetic Equivalence: no difference between having a prosthetic limb and a fully functional limb of flesh and bone.

In the World of Prosthetic Equivalence, the debate wouldn’t be “Should people with LL/D have access to this technology?”, but rather, “Can we deliver it to them in a way that’s economically feasible?” The only barrier to utilization by all individuals with LL/D would be cost-related factors. I don’t think you’d see any philosophical obstacles to providing people with such devices. But the World of Prosthetic Equivalence and the future Hugh Herr describes are, I think, quite different. (Not better or worse – different.)

2. the world of prosthetic augmentation

In the World of Prosthetic Augmentation, the replacement limbs received by people with LL/D would enable them to do things that able-bodied individuals couldn’t. A prosthesis would now imbue them with capabilities beyond that or fundamentally different than that of a normal human. Whether Herr’s statement that “[i]f the Paralympics accept advances in technology, there’ll come a time when the Paralympics will be more popular than the Olympics” proves true or not, his vision of augmentation raises some interesting questions that deserve consideration.

Before I dive into that analysis, one caveat: the views that I’m expressing are mine and mine alone. I don’t pretend or imagine myself to be the voice of the LL/D community on this (or any) topic.

a. do people with LL/D want to be something more than able-bodied?

I don’t get excited about the possibility of being able to do more with some future prosthetic technology than I ever could as an able-bodied person. I suspect that opinion finds its roots in how I chose to reconstruct my life after my accident. My primary rehabilitative goal was to navigate the able-bodied world without detection. I wanted to become what I had always been – “normal.” (Insert your own joke here.) Or, stated another way, I wanted to fit in, to be part of the universal Us as opposed to Them.

Now, I will freely admit that my attitude towards prosthetic invisibility may, at first glance, appear hypocritical. I’ve never wanted or used any kind of silicone skin over my prosthesis. The longer I’ve been an amputee, the less I’ve cared about cosmetics, to the point where I totally eschew any kind of cover today. But I think there’s a big difference between being comfortable with how something looks on the one hand and how it functions on the other.

I’ve written about ego before. I now choose to show my “bionic” left leg, a decision that generally attracts attention. And if I’m completely honest with myself, I’m ok with – perhaps I even need? – attention like what I heard a young woman whisper to her girlfriend as I jogged past them on the banks of False Creek in Vancouver three weeks ago: “That’s so cool!”

But putting aside my rampant egotism for a moment, her statement leads to an interesting question. Why is running on a prosthetic leg so cool? The reason – both in my own mind and, I suspect, hers – is that I’m doing something that’s generally understood to be unusual (i.e., difficult to do). Running leg over leg as an above-knee amputee just isn’t easy. As a result, few people choose to do it. And that makes the sighting of one of Us running a noteworthy event.

However, when technology fundamentally changes that dynamic – makes it easier for me to run faster and farther than an able-bodied person – it’s no longer “cool” in the same way. At that point, I’ve transitioned from “trying to make up the gap” to creating a new one. I’ve moved from, to say it bluntly, the freak who’s trying to replicate what the able can do to the freak who’s using mind-bending technology to separate himself from what the able can do. Instead of being a guy doing something incredibly difficult, I’m a guy who’s enhanced – augmented – beyond what’s physiologically possible. For me, that would feel like I’m gaming the system.

To be clear – I’m not saying that such a development would lack some form of objective utility. But focusing solely on how such creations would affect my sense of self, I believe that augmentation beyond what’s normally (humanly) possible would so fundamentally change the nature of the underlying activity that I wouldn’t want to engage in it.

Reading Hugh Herr’s comment, I get the sense that he might welcome operating outside of those physical boundaries that have historically circumscribed human performance. And that’s not a “bad” or “good” opinion in my view. It’s just one that I can’t get comfortable with. And I’m curious how the rest of the LL/D community feels about it.

b. will the able-bodied population accept the kind of augmentation that Herr envisions?

I can already hear the reaction of many people with LL/D to this question: who cares? Navigating life with LL/D is difficult enough without trying to take into account how the “temporarily able” view you. But this is an important issue that, I fear, can’t be easily dismissed.

Just look at the debate that has restarted as a result of Oscar Pistorius’s successful qualification for the upcoming track and field World Championships. At the same time that many are celebrating his accomplishment, you hear a steady undercurrent of discourse about the purported advantage provided by his “blades.” Even the scientists who studied Oscar have staked out violently opposing positions, as illustrated by these point/counterpoint pieces in the Journal of Applied Physiology. (Herr is one of the scientists who is part of this debate.)

All of this, I think, only underscores the legitimacy of a question I raised almost a year ago:

In a world conditioned to see successful individuals with LL/D as “inspirational” and/or “heroic” – largely, I suspect, because of the able-bodied perception that the disabled are nobly striving to overcome the limitations thrust upon them – how will people react when they see these previously brave souls blasting by them on a track or regularly accomplishing things physically that people with all their limbs cannot?

Just imagine, for a second, the debate that will ensue if Oscar actually qualifies for and medals at the 2012 Olympics. If the most informed people in the world – the scientists who studied Oscar – can’t agree on the issue, I can’t foresee the court of public opinion peacefully resolving it. In fact, as I’ve stated before, I fear that the most groundbreaking future physical achievements of the LL/D community – those that involve surpassing the best able-bodied performers – will result in a hard backlash against the previously “inspirational”.

I’m not saying that the quest for that level of performance should stop or that some individuals shouldn’t embrace pushing those boundaries. I am saying that we better begin to figure out how to articulate a message around what that actually means. Because if we wait until that day comes to start figuring it out, I think the story will have already been told. And the narrative won’t be one that people with LL/D like.

c. how will augmentation impact access to prosthetics?

Moving from the more theoretical to the practical and, coincidentally, into my area of professional interest, how would prosthetic devices that augment performance affect the LL/D community in the real world? In particular, since most people with LL/D depend on governmental or private payers for their prostheses, how would those payers respond?

Anyone who has tried to get a prosthesis paid for over the last decade is well aware that payers – especially private insurance companies – restrict or prohibit access to these devices, even though the best ones still don’t come close to replacing the full functionality of what was lost or missing. And these same payers exclude from coverage those treatments and devices that they classify as “not medically necessary” and “cosmetic.”

I suspect you’ll have a hard time convincing many people in the public at large, much less at Aetna and United Healthcare, that their premiums should go towards the payment of prosthetics that allow you to move faster, farther, and more easily than the average “able-bodied” person. Hell, as a person with LL/D, I don’t think insurers should pay for such technologies. Indeed, today insurers only pay for one prosthesis that allows the user to perform their “normal activities of daily living.” And as the press, as it undoubtedly will, starts publishing headlines in the future like “Building Superman” and “Going Beyond Human Capability” to describe those using augmenting prosthetics, insurance companies will do two things.

First, they’ll exclude those devices from coverage. That’s my guarantee to you, today, August 15, 2011. I don’t think it’s even a close question. I’ll discuss the ramifications of that below.

Second, surrounded by the swirl of articles and blog posts and videos of people with LL/D obtaining results outside the realm of normal human physiology, insurers will perform a fundamental re-examination of those devices that are purely restorative. And if there’s any argument at all that those devices augment any aspect of the user’s performance beyond that of an able-bodied individual, they’ll be added to the list of excluded technologies, because they’ve now crossed from restorative to “cosmetic” or “high-performance.” And the average person with LL/D will suffer as a result, because legitimately restorative technologies will get caught up in the wake of augmenting devices.

So, when you strip away all the philosophical discussion and debate, here’s where I think you’ll end up. People like Hugh Herr will (and should) develop prosthetic technologies that augment the user’s performance beyond what was ever physiologically possible as an “able-bodied” individual. That will lead to insurers trying to draw very clear lines between “restorative” and “luxury” technologies that will probably limit – at least in the short run – the average amputee’s access to devices that truly are restorative. And the technology that will make normal arms and legs seem “dull”? That will be on the fringe – the cosmetic surgery of the prosthetic world – available to the wealthy and those willing to take out a loan or a second mortgage to access the prosthetic equivalent of a Ferrari – something that you don’t need to get through your day, but that many will undoubtedly want.

11 thoughts on “equivalence or augmentation?

  1. As both BTK amputee and once able-bodied runner, I would not want any powered prosthetic device that would give a real advantage – unlike this current bullshit that Oscar’s unpowered legs make him faster (even those *HIGHLY* suspect scientists disagree 100% how much faster he is, something they know is not possible to calculate).

    If a powered prosthetic allows the wearer to exceed anatomical limitations, then it would have to be in an entirely different category – not the current Olympic or Paralympic games – and move into the realm of made-for-tv athletic showmanship.

    There is not a single, NOT ONE, running world record by an amputee that is faster than an able-bodied athlete. NOT ONE. If there was this gigantic disparity it would have long been proven through many smashed records. The record, however, is perfectly clear. I am so tired of this debate whose only useful purpose is to generate noise for the sake of the noise or possibly grants for funding junk science.

  2. Richard – first, thanks for weighing in. Second, you raise a few good points.

    I agree with you that a powered prosthesis that could exceed anatomical limitations would be an entirely different category of device. I was talking with my father about this post last night before I finished it, and he made exactly the same point: it’s no longer a “sport” as we’ve historically understood it if the device fundamentally redefines what’s possible. It may be interesting to watch, it may be a remarkable technological achievement, but it’s not anything like what preceded it.

    As for your last statement re. there’s no clearly demonstrated augmentation of ability provided by today’s prosthetics, I think you’re right, and I understand your frustration with discussions that beat this subject into the ground. (Hell, as I mentioned in a post a while back, Anthony Robles, who doesn’t wear a prosthesis at all (!) and won the NCAA Division I wrestling championship had to deal with claims that he had an unfair advantage.)

    What I’m focusing on – because it’s the subject that Hugh Herr broached – is a future world in which these technologies, and the related issues they raise, DO exist.

    If you look at the advances in prosthetic technology over just the last 10 years, and at the ever-increasing rate of technological development generally in all fields, I think it’s safe to assume that it’s not a question of “will this come to pass?”, but rather, “when will it happen?” And that being the case, I think it’s an interesting issue to think about now.

    Thanks so much for your comment, Richard!

  3. I think it is happening now, in some of the things I have seen being developed for the military, i.e., exoskeletons that allow soldiers to move at high rates of speed and over dangerous terrain, etc. Prosthetics and robotics become married and blurred at times…if I were a younger man looking for a exciting future employment it would be a very attractive field.

    Insurance it a sticky wicket, and I think at some point the market and the individual will have to come to terms with practical reality. That is, I am very happy with my static walking and running feet and don’t want a power anything even if insurance provided it; otoh, I can see individuals who do not have as much mobility due to other health issues who would be prime candidates for power assistance.

    Let me put it this way: we buy cars to get around, why would I not want to finance and buy my own advanced prosthesis if I wanted something far superior/better? It may well be a larger, more competitive market that will bring prices down instead of sometimes arbitrary insurance codes that only serve to keep prices arbitrarily high and technology out of reach. Perhaps moving out of a strict medical/insurance system will be paramount to get more to the people with less cost.

    Great blog Dave!

  4. I suspect the “able-bodied” will respond to a Pistorius victory mainly by arguing over whether it ought to have a Barry Bonds asterisk next to it — though absent the moral overtones associated with the steroid scandal.

    Those open-minded enough to accept it will accept it. Those inclined to be resentful will discount it as irrelevant. The empiricists will plumb the mysteries of physics, trying to determine “with mathematical precision” (as Capt. Queeg said) whether carbon fibre really is better than human flesh and bone.

    Great fodder for Mike and the Mad Dog (or whoever they are now).

    I don’t know what any of that does to or for the philosophical arguments involved…..

    • less is more readers – I introduce you to my father, who’s a better writer and thinker than I. If you like my writing, you should thank him.

      Dearest Father – while your position is logical and reasoned, I think the debate over Oscar’s alleged “advantage” is neither. Where you and I disagree is the conclusion that those “inclined to be resentful” will simply discount prosthetic “superiority” as irrelevant.

      The terms of the “Oscar Debate” have already been set: remarkable amputee athlete (read: INSPIRING!) v. technodoper (i.e., cheater). And the latter category – particularly in the context of sports – goes to THE core issue underlying any competition: fairness.

      Here’s an example of irrelevance. In 1987, Major League Baseball saw a huge increase in the number of home runs hit. Wade Boggs socked 24 homers in ’87 but then reverted to form, hitting 3 and 5 in ’88 and ’89, respectively. Lots of players posted similar numbers.

      Most experts now believe that some change in the manufacturing process resulted in “livelier” baseballs that traveled farther that year. So people dismiss 87’s home run totals because they don’t accurately reflect what kind of player an individual was, as demonstrated by the reversion to the mean in subsequent years. 1987 home run totals are, therefore, irrelevant. No one looks at Wade Boggs and says he was a 20+ homer guy because of 1987. They just dismiss that stat as an anomaly.

      In contrast, the moral overtones that you posit will be absent from a discussion of Oscar’s theoretical success are, I believe, already in play and, indeed, a fundamental part of the debate. Oscar’s results will never be dismissed as irrelevant by detractors – they’ll be labeled “impossible.” And when people frame the debate in that way, they’re implicitly calling into question the fairness of the competition.

      So I think there’s a lot at stake here.

  5. This discussion is a prosthetic leg discussion – not one about prosthetic limbs. – Storing energy is indeed possible through elastic deformation with prosthetic legs. The same has been measured for “real” legs and there, against public assumption, elastic energy storage is next to none. So based on theory alone, a paralympic runner can indeed be faster if that is the only factor weighing in. However I would assume that no paralympic runner will want to run faster just because of that – running fast at that speed is above all extreme work, it requires massive to insane training levels and if you do not have to improve by that extra fraction of a second, you will not do it. Doing the analog activity in water (I currently train fly using a Lunocet 015) can teach very valuable lessons but this would go too far here. But I doubt we will see any paralympian runner actually taking advantage of the energy storage to the level of being faster than a non disabled person – it is just too much of a hassle. However and inasmuch as prosthetic arms is concerned – industry cannot even build sustainable and reliable tools. Leave alone hands. Inasmuch as the existing tools are concerned they can be perceived as “better” than real hands for every isolated and single features such as a hook being insensitive to heat when handling meat on a grill. With prosthetic arms and generally, all we get are Potemkin villages. New controls mean “more stuff” and usually, all that disables rather than enabling anyone. So from angle of wearing prosthetic arms, even “equivalence” is some 100 or 200 years away, “augmentation” is absolutely nowhere except in some people´s dreams.

    • swisswuff – you raise too many points for me to address here completely, but there are two things you say that deserve a response.

      First, you’re right: while I generally talk about prosthetic limb augmentation in my post, the current state of technology effectively limits the augmentation debate – TODAY – to lower limb devices. So point well taken.

      Second, I think your estimate that upper-ex equivalence is a century or two away is overly conservative. If I were a betting man, I’d say we’re looking at equivalence in the upper-ex space in 40-50 years. Of course, that opinion is worth exactly what you paid for it.

      For those readers of less is more who are looking for more info about the upper extremity space specifically, or just a provocative viewpoint more generally, swisswuff’s blog is worth a look: see, e.g., http://www.swisswuff.ch/tech/?p=299#more-299 (on the subject of hype v. reality).

      swisswuff – thanks, as always, for reading less is more and for your thoughtful comments. In 50 years, if we haven’t achieved upper ex equivalence, I owe you a drink. I’ll be 92, drooling all over myself, and navigating the world in some sort of integrated prosthetic/standing wheelchair combo by then, but I’ll track you down and live up to the commitment. 🙂

    • This is no power produced in storing of energy on carbon fiber feet, only loss in the form of heat. The energy production of the muscles far exceeds any that is stored and then lost through heat transfer. So no, it is not possible for dead legs to produce greater (any!) energy, only mitigate the loss, and other muscles have the additional energy load requirements placed on them for things like balance.

      One of the points Oscar’s detractors mention is he can “reposition” his legs faster than able-bodied athletes. I have always understood the terms “turnover” and “stride rate” used, meaning elite athletes can do this at 185 – 200 steps per minute. I have never seen Oscar’s numbers…is he able to exceed this seemly anatomical set point? This could be discerned by simply counting his footstrikes for 30s x 2 in one of his 400m races, but I haven’t seen a full, high def video of only him running that I could use for this purpose.

      (Dave, do you know what Oscar’s turnover rate is? Anyone and source?)

      I will say I have seen bilateral runners running tall, that is, what appears to be tall prosthesis for their build. This would give them a longer gait and if they are able to maintain turnover rate, then there may be something to investigate. Still, none have set records faster than their able-bodied counterparts. NONE.

      I do not know what you would consider “insane levels” of training. They do not consider it a “hassle,” it is the price paid for excellence. Most elites push right up along the edge of injury, the body will at some point break down and demand repair.

      It is very difficult for the amputee runner athlete (and others) to push as hard all the time as even the best prostheses will sooner or later cause trouble. The interface with the residual is quite dynamic at times with volume changes, stride adjustments, sweat production, etc. It would almost have to be an intelligent exoskeleton…there are some good ones available and more to come.

  6. Richard: I don’t know the answer to your questions. I do remember that when the IAAF barred Oscar from running a few years ago – a decision that was later reversed – one of the arguments that was made was that his legs allowed him to achieve a stride length that was much longer than an able-bodied runner, allowing him to cover more ground with less effort.

    On my own, I watched a video of Carl Lewis setting a WR in the 100M and Oscar running the 100M at a local meet. Using this entirely unscientific method, simply counting steps over 100M, it appeared – and I emphasize, appeared, because counting the number of steps these guys take at full speed is hard to do – that Oscar took more steps than Carl Lewis (i.e., he had a shorter average stride length).

    This is not in any way a scientific result. There are a million variables my methodology doesn’t account for (e.g., Carl Lewis is a LOT taller than Oscar, Oscar’s stride length at the beginning of a race is likely different than at the end when he’s at full speed, etc.).

    Assuming I counted correctly, the only thing this proved was that Oscar’s average stride length over 100M wasn’t longer than Carl Lewis’s.

    It was an interesting exercise, but clearly we need to defer to the scientists. Only problem with that, of course, is they disagree with each other.

    So my basic position is this: if the scientists can’t figure it out by looking at Oscar-specific data, we’re unlikely to figure it out in the comments section of less is more. 🙂

  7. Springy technology necessarily constitutes a great aid for propulsion. Using muscles must be more energy consuming. I assume that training practices of nondisabled athletes may be quite merciless and advanced; if a paralympian trained that way, running style would also take full advantage to convert that spring capacity to speed. For that, the sprinter should probably use weights for some training series while running to improve spring compression and jumping power, and most likely work on core strength a hell of a lot harder than non disabled sprinters. With the same determination that we see with contemporary crawl race swim style evolution I’d really expect Ossur and Pistorius to go faster and a bit more creative. But as I said – gaining extra speed at that level of performance definitely requires what I’d call “insane” levels of dedication and training – even more mental adaptation, harder sets, more muscle groups, higher frequencies. The cheetah legs appear to be a good start but athlete’s running technique may require some more speed tunings. It is not just the prosthesis that empowers, it is also the unbroken spirit that must be channeled to full speed.

  8. In 50 years I’ll be 94 if still alive and somehow I am afraid of old age, disability and all chronic illness that may come. Probably by then, upper extremity amputees will be allowed 1-2 immigrant servants by insurances — far cheaper and more effective than prosthetics. And maybe cooler. My guess is that we’ll see creative workarounds and better tools. But no equivalence to a human hand with wrist and fingers. No precise enough control, and no power.

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