"Prosthetic culture": prosthetic solutions by non disabled people versus prosthetic solutions by amputees [upper extremity]

"Rehabilitation professionals define the problems, the agenda, and the social reality of disabled persons in ways that serve their own interests more closely than those of their clients" (Joseph Stubbins, "The politics of disability" --- In "Attitudes Towards Persons With Disabilities". Edited by Harold E. Yuker. New York: Springer, 1988. pp 22-32)

It appears as if we may want to look at some ad hominem observations. After all, there are not so many people that work towards upper extremity prosthetics and that achieve success with their attempts. Let's have a go at it, shall we.

Non disabled people


Otto Bock and Touchbionics come to mind. These sell highly priced low-tech products. Their flagship if not their only products are myoelectric prostheses. These have an enormous margin of financial income over the relatively cheap parts that are used. Check out the bolt odyssey or the battery joke.

A below elbow amputee prosthesis featuring Touchbionics' iLimb hand costs a whopping 78'000 CHF here. Because there is no cogent reason, no clear and distinctive performance that hand delivers that enables amputees, insurances here can not cover it.

Some of Otto Bock's body powered parts leave a bit to be desired; more details can be read on this website. Mark Lesek in Tasmania observed that his German prosthetic part manufactured arm parts kept breaking down but no one there was allowed to fix it or even take it apart; sending the arm to Germany would cost $6000 each time. Pricing is hugely prohibitive, functionality compared to the pricing is poor.

DARPA currently seems to invest all of their money into myoelectrics - no body powered technology is investigated. Instead, one of the program heads referred to hooks as "something out of Peter&Pan". Yet, no product is anywhere near the market.

I cannot even wear such an arm at all - for long stumps, pin lock liner systems are not integrated with wrist units. And the hard socket sends me down pain lane for good.

The dynamics of non disabled people working for prosthetic industries (not other non disabled people, no) has it that they are, excuse my French, rather often simply not able to conduct a constructive feature focused dialog with their customers. They do not appear to transcend their fantasy that amputees lack a body part and their brains and that, in fact, a physically disabled person is like any other person, just physically disabled. Strangely enough, most people outside of these companies do not seem to think like that - which begs the questions of what people work in prosthetic companies, what is their key issue about respect towards the disabled, and why. I'm not saying I wouldn't know some very disturbing answers here - but those seem to be the questions.

Ossur makes nice liners. For my Upper X liners, I cannot prevent the outer fabric to detach from the silicon after about 3 months o wearing but I have been told not to worry about it.

Body powered technology emerges as Brady Veatch of Physionetics at ADA Technologies builds parts such as the massive V2P prehensor. Even though I had shown Brady a lot of my new MovoHook's features right after I got it, and even though I had explained details to him for over half an hour on the phone, he did not yet get around to let me test his prehensor or see images up close. Another non disabled person that seems to have some difficulties to navigate the amputee community fairly.

What are we to you all, a business idea of the cheap exploit and cheap manufacturing variety? No business ethics required because we cripples ought to be happy you look down to us to reach out and give us a hand? Is that the deal? Is it "Otto Bock - quality for life" or not much rather "Otto Bock - quality for up to a couple of weeks"? Is it "Touch Bionics - Get a Grip on Functionality" or "Touch Bionics - Get a Hold of A Whole Lot of Real Money"? "ADA Technologies - Taking Today's Technologies Into Tomorrow's Markets" or maybe a bit more precisely "ADA Technologies - Taking Technologies"?


All times had their robotics or informatics departments come up with their own "hands". So, how far is the human hand, we reluctantly ask...

Arm amputees

Myoelectric arms are well known to many users as having issues (politely put) to unacceptable (directly put). Best experiences are often made with pin lock liner systems and body powered technology unless the state, shortness of loss of power of the residual limb requires electric amplification of muscle signal.

Bob Radocy: He implemented TRS and sells a prehensor along with a number of other sturdy specialized body powered parts. Prices are reasonable.

Jon Kuniholm: He researches electric control at the Duke University in Durham, North Carolina. He appears to wear body powered arms and founded Open Prosthetics that almost exclusively deals with mechanical or body powered solutions. He recently published an article in the IEEE Spectrum Online journal. All output of Open Prosthetics is free.

Mark Lesek: He wears osseointegration. He built his own robot arm and appears to work towards a sophisticated control mechanism.

Dan Horkey: Dan is an artist who specializes in prosthetic artwork. He is the person in charge at Global Tattoo Orthotic Prosthetic Innovations.

Ron Farquharson: He is a right below elbow amputee. He manufactures a lot of sturdy prosthetic parts through Texas Assistive Devices.

Myself: I developed the MSM wrist together with some friends. It is extremely stable and extremely fast to swap terminal devices. The MSM wrist 0.1rev plans and CAD models are free for download and you are free to use it in its original or any modified version and have it manufactured wherever you wish. I am not doing this for income, and there are no contracts or ties to any companies. The milled and ready to mount metal version of our wrist unit can be ordered through MDP Meili at production cost. Besides, my observations and trials, conclusions and remarks are available freely right here.


The non disabled people driven products tend to be by and large characterized by what appears to be massive overpricing and poor technology, poor design and poor material.

Dealing with these people can definitely make you feel inferior as they may intimidate, threaten or overcharge you. Prices are huge, people can be very hard to deal with and merchandise may definitely not be worth that much.

Yet, basic design ideas and a thing to start off with are worth something. Also, not all products are all bad. Some are perfect (I like Ossur liners without modification). Some of their stuff simply does not work at all - Otto Bock's 2-way pull hand and their MovoWrist both died within the first couple of minutes. Some stuff needs repair directly after purchase, such as Otto Bock's MovoHook joints require a substantial redo. And Otto Bock's cable clamps or plastic harness sheaths need replacement before putting them to use. The bolt / wrist combos cannot be recommended, so after asking the company for their opinion and reading their reply I got the impression they do not understand "quality for life" issues at all and we started to build our own.

Academic subjects tend to be driven by questions of non disabled people rather than solving amputee issues.That way, research funding is given to projects that society sees as "helpful" but really can be a big waste of money.

Amputees seem to solve arm issues differently:

  • For long residual limbs, mechanical or body powered solutions and maximum sturdiness appear to be highly valued. That is in contrast to the substandard quality we see produced by big companies. Among body powered solutions, a variation of different hooks are at the center of attention. Some prefer voluntary opening, some prefer voluntary closing, and some prefer the combination of closing, locking and opening action provided by products such as the APRL hook. Everything should bedesigned and built to be rock solid and completely reliable. Arm amputees know that on top of the stress of being disabled no one needs the additional stress of being shown up by crappy parts. No industry lackey grasps that, as it appears.
  • For short residual limbs, osseointegration, targeted innervation, myoelectrical solutions and complex control are key issues. Likewise, serious engineering is key (as for people with long residual limbs).
  • Good looks may not mean a full similarity to anatomical norm. It may, but it may not as well.

General problem identification

Obviously, I see a problem in the current "prosthetic culture".

The problem is defined by not checking the quality of orthopedic solutions against engineering standards, by not checking prices against actual value, and by not holding manufacturers accountable.

The culprits would be the people that underwrite the end product. They consist of the customer (who has the obligation to complain and make her or his case just as I do this here), the prosthesist (who may not check for alternatives if parts fail repeatedly), the insurance company (who may pay excessive prices without having their claims manager open up their own tool and parts shop in their backyard) and also the companies that may monopolize and bill excessively. Legislators and politicians may be responsible for the legal framework and so if a prosthetic solution requires full medical accreditation and costs an arm and a leg (ha, ha), how can it be that manufacturers do not guarantee 40 years of 100% functionality under exactly defined circumstances?

Concise solutions

  • Customers need to become self assured. That is not easy, and amputation is a particularly difficult situation to deal with in terms of being self assured. Customers need to be educated as to the options and results, as to what is worth what, what is a valid demand. Customers need to know, for example, that it is their personal duty to make sure they get a good fit for their socket. They need to insist to get a fitted prosthesis. They need to learn how to insist. That may not be easy! It took three people in my orthopedic technician's office including some superiors to acknowledge that my first prosthesis was almost 3 cm (!) too long. Go figure. And we need to fairly acknowledge that we are being stereotyped, discriminated against and stigmatized. Even if that much seems clear, it is hard enough to address any actual communicative issues.
  • Orthopedic technicians want to see happy customers. They need to keep up with news. They need to know where to order parts, how to mount them and how to instruct their customers. They need to learn that big companies offer expensive parts that may fail fast and that in each individual instance, other solutions may be better. They need to read up, be given updates and creative new ideas.
  • Insurance companies need to know. At least I make sure that my claims manager knows as exactly as possible. And from these experiences I know that they like products that work better and that are cheaper far more than they like expensive parts that break down quickly.
  • Companies that manufacture prosthetic parts need to respect laws. In Switzerland, we have a cartel law that prohibits a range of marketing and sales behavior. Other countries may have similar laws but until these are used to prove a point, existing "prosthetic culture" may not change. Also, customer representatives should learn about their own tendency to belittle and laugh off the cripples - it will cause customers to get real angry. I am not talking about hot anger here. I mean the "best served cold" variety.
  • Legislators and politicians need to be careful to combine various levels of activity with various levels of restriction in a clever way. Free market is a good thing, but so are free education, and nondisabled people may make for really bad advisors when it comes to upper extremity amputation issues.
  • Researchers should find out about concise problems to solve. There is a lot of fun to be had with theoretical research but don't waste applied research funds and hopes of disabled people.
  • Research councils and ethics committees should view upper extremity prosthetics research with great caution. Again, nondisabled people may make for really bad advisors when it comes to upper extremity amputation issues.
  • Detailed specifics. I believe that what really matters are detailed specifics. General and broad terms, insurance policies, sale phantasies and other tricks are nice and sweet, but ultimately go exactly nowhere. Otto Bock can advertise 'quality for life' for all they might - if their detailed specific bolt diameters are shown to be off the mark it's quality to throw away right now and right here, end of story. I can advertise Red Hand ideas for all I might - if I use the wrong solvent or color, the plastic hand melts and will be converted to Red Trash right now and right here. So we all require detailed experience reports, documented success and failures, experience reports from the front. Detailed specific information is key and in my view is the only real value that constitutes a true constructive contribution to the subject of upper limb prosthetics that I am genuinely interested in.

Cite this article:
Wolf Schweitzer: swisswuff.ch - "Prosthetic culture": prosthetic solutions by non disabled people versus prosthetic solutions by amputees [upper extremity]; published 21/06/2009, 01:49; URL: https://www.swisswuff.ch/tech/?p=181.

BibTeX: @MISC{schweitzer_wolf_1638800977, author = {Wolf Schweitzer}, title = {{swisswuff.ch - "Prosthetic culture": prosthetic solutions by non disabled people versus prosthetic solutions by amputees [upper extremity]}}, month = {June}, year = {2009}, url = {https://www.swisswuff.ch/tech/?p=181} }