Hugh Herr and the rest of the world [phantasy talk, science fiction, hype]

Hugh Herr is a double leg amputee who comes up with new prosthetic designs that are out there in terms of manufacturing and selling to everybody - far too complex, far too expensive.

But great promises go along with them. From these, he and contemporary "bionic limb" representatives generate these utterly unrealistic trumpet-sound like promises that sound too good to be true and they are always the same.

If these hype aficionados restricted their trara to prosthetic legs it'd be alright as sooner or later they sure could advertise to build a 3000 horsepower leg system that propels people at jumbolino airplane speeds - but inasmuch as prosthetic arms are concerned, I take a personal interest (remember the title of the blog here that you clicksed on?).

So interestingly, i-Limbs and its likes also repeat to be mentioned - apparently a "bionic" hand is "bad ass" looking. Well, by the sound it is not bad-ass at all. It may be bad ass looking maybe to some people that never stopped playing with puppets, but entirely useless to do anything even remotely real bad-ass for everyone out there.

To merge man and machine, that was what part again that Hugh Herr wants to merge to the man? Yes that part? Ah, a "machine". Now, that's gotta actually be a machine in the very narrow sense of the word: a functional well designed, well engineered piece of engineering that actually functions (rather than just visually represents) to accomplish a task and to perform work. Let that melt on your tongue before moving on (we are talking about prosthetic hands and arms, right? remember the title of my blog?) - p-e-r-f-o-r-m  w-o-r-k.

With that, Hugh Herr is challenged to cut his (or, better, my) hedges for 3 hours non-stop, including over the head works, with a 3 kgs hedge cutter machine (machine, work, remember?) (mine's a B&D) and optionally (a) his much-beloved and often-cited iLimb with a Munster socket all shee shee froo froo with carbon fiber and stick-on flowers if must be, and (b) a body powered arm with a specialized Puppchen wrist, a modified V2P Prehensor, a newly designed cable control and a specialized shoulder harness. My bet is that he might find out after about 40 minutes what I knew without even going there - but we all learn at different speeds, do we - and that is, that solution (b) by *very very very very very far* wins over any solution (a). The thing is, I know such things sitting at my desk or just anticipating not emotionally but rationally, considering thoughts, theory, and imagination - others will never know until they spent their money and learned the hard way.

Peter asks "Mommy, why do I always have to repeat mistakes other people already did?" - Mommy says, "That is because one can learn from mistakes!".

Maybe Professor Herr should restrict his ideas to legs only and make sure that he does explicitly NOT address arms or hands where he cannot possibly have any particular ideas regarding everyday integration and how it feels to have that feeling, or, not so much. Hugh Herr is in business since a while now, and prosthetic industry - other than releasing largely useless "bionic" Potemkin type hands (i.e., they just look loke that) they failed to innovate upper extremity prosthetics in the las 20 years. That includes the time when Hugh Herr served as a person to shape the ideas of prostheses. And so to now include prosthetic hands and arms in these hype-generating hot ballons, that is to invite a flogging here.

So what are Hugh Herr's propositions:

"I predict that as we march into this 21st century, the changes we'll see in prosthetic designs [will be that] the artificial prosthetic will become more intimate with the biological human body. There will be a mergence, if you will."

""It's actually unfair," Herr says about amputees' advantages over the able-bodied. "As tech advancements in prosthetics come along, amputees can exploit those improvements. They can get upgrades. A person with a natural body can't.""

So let's look around for "upgrades". Anyone selling? Oh, the answer is "no"! Oops. Does Hugh Herr know about there being no fully integrated options around for prosthetic hands? I mean, not even remotely close? Does the public know? Do they all run after the same strange dream? Currently, Otto Bock and TouchBionics all neglect their only option to make that promise of 'merging man and machine' come true: body powered technology. It is fascinating to watch as these companies dig their own graves. But it is not stoppable.

Amputees will rehabilitate faster, better, healthier

The future amputee compared to the amputee 50 years ago is far stronger and healthier. The future amputee will be far more conscious regarding body balance, nutrition and exercise and many already started today. Amputees today are much better networked than 50 years ago. Not everyone will go all the way, but on an average, the amputee of the future is self asserted and so strong - with body core and remaining extremities - that they might beat any non-disabled average person with any of these properties.

It will be a further development of a few years and then, more amputees will require as kick-ass type arms as they already require prosthetic legs. That doesn't mean there won't be gadget-lovers that will continue to prefer permanent fiddling with their prosthetic arm just like some people require permanent fiddling with their iPhones - but for the most part, body powered arms are in for the long haul as they are the only way to maintain graded, low energy and low weight solutions.

With amputees living up to their nineties, elbow and shoulder problems are far more of an issue than 100 years ago. Rotatory cuff problems will be a lot less if the prosthetic arm is not one of these shoulder-killing myoelectric anchors that will rip your tendons out on the long run. If you want to grow old and stay fit as arm amputee, today, you will be against all the industry tries to sell you - and they are in it purely for egotistical reasons. Hugh Herr is in it for the media hype, but none of these folks look out for the amputee that lost an arm.

There is currently no similar hand or gripper as there is a Cheetah leg for the running leg amputee. It is a matter of time before that demand exceeds what current industries offer. The V2P Prehensor, the TRS Adult Gripper and the Hosmer hooks come close but not quite. The Becker hand is a great and very well developed piece. But there is not modern match to Cheetah blades.

No one is crying after more and more perfect appearances (see below, why that is) - but what is on the rise is a demand for kick-ass (to Otto Bock and other verb twisting companies: to you that spells out as "ultra giga extreme heavy duty", that is, something you never ever built before) functional prosthetic arms.

Amputees will fight for recognition as equal humans not on the appearance as other humans but on a functional level

Social recognition never comes through optic / visual blending in but over performance. I am pretty decided on this one. Amputees already are, given the rarity of our disability, over-represented in any kind of media attention which means that the visual stigma is a major problem that is impossible to overcome visually for the most part - it can only be overcome functionally.

The leg amputee community shows us that. Social recognition allows for visibility of prostheses or even requires it - non-disabled people are stressed out far less if they can visually identify a disability from afar and can adapt to it from safe distance but they can be extremely irritated if the disability becomes apparent suddenly or too late, too close for them to manage their shock or emotions. Social recognition requires your prosthetic to be as functional as they can ever be, and technical visibility is not an issue.

Myoelectric arms (which I call "anchors") of 1,5 to 2 kg weight with center of gravity at the palm of the hand or wrist and a cost of up to 120'000 USD a piece are a joke. You cannot even have symmetric posture with that. You will sweat and be dripping wet with these before even touching the shovel or whatever it was you wanted to touch to do some real work.

No, recognition and respect is the new social currency and with that, myoelectric arms - that have their clear limits - remain a niche product. The real run for the hill will happen with heavy duty unwreckable body powered arms. Besides they are the only way to actually achieve body-machine integration from a functional view point.

Before irritating gadgets are entering my life, I will manage without prosthetic arm. It is a myth that one needs one of these for many activities of daily living (ADL) anyway.

Amputees will go with whatever does merge to their body

Functionally, body powered arms are comfortable, they blend in with the body muscles, they are relatively to extremely reliable and after a rather short period of time the user can forget about consciously controlling them and take it from there.

Merging machine to the body I need these:

  • extremely well fitted socket (I have that, Ossur Upper X liner, pin lock, carbon fiber or epoxy socket of low eight and tight fit) (my myo arm has a hard Munster socket that does not fit that well)
  • no restriction on my elbow joint (my current socket has that, it is fully suspended with the silicone liner) (my myo arm is a Munster style socket that painfully restricts the elbow, what is considered "normal" by people that know these sockets)
  • correct anatomic length for prosthetic arm (if not a bit shorter) (I have that despite a relatively long stump) (myo arm: no electric wrist unit is known to fit here)
  • sturdy quick swap rotation wrist unit (I have that, we built our own) (none of the other parts are sturdy enough, we tried)
  • very robust and subtle yet long lasting cable control (I re-designed cable control from scratch, the setup now uses high tech parts and works reliably for periods of over 6 months without break) (no commercially available cable control does that)
  • very comfortable and sturdy shoulder harness that does not compress brachial plexus (got that, we redesigned this part and got it out of the way so far)
  • terminal devices that are very reliable (Hosmer hooks, Becker hands; to a part V2P Prehensors) (but no Otto Bock or other aprts; these are mostly for very light use or just showing off).

All failure, particularly sudden and / or premature failure in comparison to cost of the device, is perceived as highly and extremely irritating. As some myoelectric arms cost a fortune and more than three cars (each of which might have a manufacturer warranty of three to five years), one clearly expects a failure free period (or one covered by full warranty) for at least three times three to five years, that is, 9 to 15 years. But prosthetic manufacturers don't give you even that - they also limit usage and loading for your prosthetic arm.  No way brittle luxury gadgets that irritate permanently can grow to be a part of yourself. It is part of their loud and irritating advertising, definitely - but it is as far from a daily experience as it ever gets.

Campbell Aird (page 157, "Enabling technologies - body image and body function", by Malcolm MacLachlan and Pamela Gallagher) says that his externally powered prosthetic (an early version of the i-Limb) does not feel as a part of him in the same way his original (body powered) arm does. He states that the thinking required to make an externally powered prosthetic arm is very different from a natural or intuitive control, and to make it work, he has to flick a lot of different areas of his houlder, so he would be conscious to make it work all the time.

This is my experience as well.

Arm amputees are not dress-up puppets who offer all body areas for prosthetic arm control, instead they require minimalistic setups like everybody else.

The thought that I will wear a beanie had with wires sticking out, that I will place a foot control into my soles, that I will want to have electrodes all over my body and carry a 5 kg battery with me - that thought is entirely ridiculous.

At the time of full integration and clever integration, the solution to my missing hand and forearm must restrict its anatomic placement to that area. That is a hard requirement.

Diverging requirements

Current industry tries to push hard with their new "bionic" hands. With these, they sell really cheap motors and really cheap circuitry for ridiculously huge sums that no insurance when evaluating "bionic" limbs such as the Otto Bock Michelangelo, the Touch Bionics i-Limb or the RSL Steeper BeBionic should ever neglect.

With consolidating economies globally, insurances will not afford useless luxury trinkets such as these "bionic" Potemkin-hands at the current prices - and if they do, some corrective or overseeing body should definitely correct these wrong decisions.

The resulting prosthetic arms are clumsy, still look awkward (just as prosthetic arms always do), really loud and irritating, extremely sensitive and brittle and not ready for any halfways reasonable work in any way - so, to buy one is a dumb idea all around, for anyone with all of their senses. To buy one is at best like getting a luxury item for the ones that don't know where to spend money otherwise.

Compared to these huge sums, from my experience, information and viewpoint, the attainable degree of possible "man machine integration" is laughable.

This leaves the industry with little more to offer. Most of these companies already have limited or no resources for developing body powered technology. Economies consolidating globally has the effect that these companies will now die the vicious cycle that haunts them since thirty years - they abandoned solid solutions, they abandoned their customers, they have a huge failure rate with > 50% of arm amputees rejecting prosthetic arms (which is a true achievement only if one assumes the industry representatives to be perverse stump lovers or devotees, a notion which cannot be entirely dismissed given some representatives' actual behavior and should warrant a hard close look at any given time). But, their demise was decided when they figured it was all idiots that wore body powered arms and all geniuses that wore their Potemkin-type "bionic" hands. Which, in itself, is a view I find extremely hard to support.

Industry has undergone and is currently irreversibly jammed in a narrowing tunnel of a death cycle just as much as users of prosthetic arms are - and there is no way they can get out of there.

There are no high-tech mechanical grippers, no high-tech wrist units other than ours, and overall a stand-still in what is hyped as "man machine merging". The root of all evil is that industry completely ignores JUST HOW man-machine-integration functionally, from a functional view point and experience, actually functions. And for complete ignorance there is only one grade teacher will give you these days: none. You will have to spend your free afternoon helping the janitor weed out the school's garden. Make sure you bring your "bionic" arm. Bwahaha.

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Hugh Herr and the rest of the world [phantasy talk, science fiction, hype]; published 28/08/2011, 13:00; URL:

BibTeX: @MISC{schweitzer_wolf_1618203364, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Hugh Herr and the rest of the world [phantasy talk, science fiction, hype]}}, month = {August},year = {2011}, url = {}}