Normalizing prosthetic arms and media: the role of 3D printing - official statement

It is intriguing that overly massive media pressure can bring proponents of new ideas in prosthetics to crawl back.

If, as typical in prosthetic arms since over 100 years (e.g., Carnes Arm, or, Russian Arm), "new products" are hyped up to no end, this can be a logical result: expectation and reality differences are stretched until a snap occurs.

Obviously, arm amputees snap far earlier than that - but we would all not be here if we had a lobby and if respect was prevailing within the whole prosthetic arm drama that keeps us up. But, respect is a tangible issue - arm amputees are neither listened to, nor taken seriously - and thus there also is no lobby. So we snap silently. We simply abandon the crap. We put it in the corner, and find excuses. Because all prosthetists act as princesses, as they never take rejection lightly, an arm amputee is advised very well to never tell their prosthetist anything true about their prosthetic arm unless (a) it is a good thing or (b) the prosthetist can and will want to improve it. Otherwise, mum is the word. Excuse number one to not wear the prosthetic arm is "the stump is more sensible"; not at all understanding prosthetic arm rejection, robotic engineers now put even more crap into the crappy arms, furthering the alreay dead death cycle (link) - but we usually snap silently, or as is the case with Mark Lesek, Bob Radocy or me, start to build our own stuff.

However, once press gets involved more heavily, the snap between diverging expectations and realities is considerably louder.

The drift would not be just as considerable were the engineering good. But the dire engineering situation is illustrated by the fact that some prosthetic arm companies may spend far more money on getting their faulty and deficient product marketed, which includes representation by paid amputees, than they spend on engineering. So it is just a simple matter of time to see that "business model" fail to a degree where open statements may become a sensible way to try peace. They start by "giving you back a new life with this "new" hand" and end up admitting that you cannot even take the trash out with it. So far, the manufacturers created "dreams" and "assertions" and the users had to put up with it, or (as me) started to heavily criticize what has to be heavily criticized. And now - surprise! - here, we read that the 3D printed hands are expected to be quite possibly just worn for a day or two - not written by users, but by representatives of the manufacturers within the "3D printing of prosthetic arms" community.

Quite frankly, asking others within the community and watching proficieny levels at get togethers: the same is true also for other prostheses than 3D printed hands; no one also wears their "bionic" arm so they actually use it. Of course not! That thing is just always in the way, heavy, no useful grips, and too expensive, with massively fragile gloves - you best keep it in the cupboard and even there, it just falls apart. Mostly, the silent snap, as outlined above.

However: the representatives in this instance (3D printed hands) have little to gain financially; the whole 3D printing business by the very outset is a low budget approach. Once it becomes clear that one cannot make a lot of income one does not lose much - financially - by declaring technical bankruptcy either.

This is not the case for "bionic" and robotic hands, where military and space exploration applications as well as insane price tags distort the situation significantly from a user perspective (user of a prosthetic arm, as seen from viewpoint of a right below elbow amputee; did you read the title of this blog? did you come here on your own? are you lost?). Prosthetic technicians that earn 20-30% on all hardware have a clear financial conflict of interest (that is rarely ever declared) and of course, they will do all they can to sell 80'000 CHF priced "bionic" hands rather than 6'000 CHF "body powered" arms - particularly as the "bionic" arms need far more extremely costly maintenance, upkeep, repairs and so on. Unless that financial model is changed, we can not expect these people to declare their conflict of interest, or, to admit that what they do basically attempts to further their own interest against that of arm amputees, and against that of the general public that is tricked believing that "bionic" is the future. Now, is it? Have we understood the technical details? Never mind, they "give you life back" as they say but really, suck empty the pockets of hope, and the suitcases of money. To get the salesforce behind "bionic" hands to admit to their technical mistakes and flaws will - in all probability - be not nearly as easy, just asking friendly questions certainly has not helped so far.

The clear identification of actual problems however is the sine-qua-non requirement for any improvement, and improvement is very necessary. That is why this statement from the 3D printing proponents is so relevant: it comes from an unlikely source.

My personal view on 3D printing is that it is most useful for development and testing shape match - but for actual usage and real world application testing, manufacturing methods need to be used using materials that actually allow for actual usage and real world application testing. Material strength requirements can be considerable for prosthetic arms, so I would use 3D design / print / revise design / print cycles to approach the optimal 3D shape to be built, but then get it produced with a better material - be that more flexible (rubber, silicone, PVC) or harder (milled steel, other). Once one starts from that angle, all of a sudden, textiles, wires or tubes are just as good as 3D printing as they allow for rapid approximation of a prototype that may have enough stability and comfort (after all a prosthesis is worn by a human) so it can, actually, be tested in real life. So it is no surprise that this website (among other tips) features a great method to turn 3D shapes into 2D cut patterns: this is a far less resource intensive way to also, very effectively, build prototypes from useful materials.

To restrict oneself to just one single method (3D printing, that is) of prototyping prosthetic arms seems unnecessary unless, of course, society places symbol value (rather than real / actual value) on the method and its 3D printed simulacra (read on the wicked problem of separating symbolic from real value here).

Furthermore, the current obsession with 3D printing of hands rather than grippers or hooks seems to also build on old hook man legends that vilify certain aspects of disability; not consciously reflecting these societal sub basis narratives can also significantly impede progress in technical directions that have seen massive hype, massive fears and  massive avoidance of *actually* achieving viable solutions for arm amputees.



Dear Listserv,

We would like to address the concerns that have been recently posted about 3D printed  prosthesis and orthosis. It is our to hope to minimize the fear that 3D printing will disrupt the care that Orthotists and Prosthetists provide.


I am Jeff Erenstone CPO, the founder of Create Prosthetics and owner of Mountain Orthotics and Prosthetics. Recently I was nominated to serve as Chairman of the New Device Board for Enable Community Foundation. Here is an article about my work with Enable Community Foundation (ECF) and my recent presentation at the United Nations

Also contributing to this response is Andreas Bastian, a senior research scientist with the Integrated Additive Manufacturing team at Autodesk <>, one of the world’s largest design and 3D printing software companies. At Autodesk, Andreas researches existing and novel additive manufacturing technologies and workflows and explores how a systems approach to additive manufacturing can unlock new capabilities, such as the dramatic advances in speed and scale in 3D printing made possible with Project Escher <>. Additionally, Andreas is a Director of the Enable Community Foundation <> (ECF), a non-profit that seeks to develop and deploy orthotic and prosthetic devices using 3D printing to those without viable health care alternatives. Andreas spearheads ECF’s technology development and design research programs and works closely with Jeff both domestically and in the field.

On Media Coverage of 3D Printed Devices

It’s important to distinguish the media narratives about this work from the work itself. There are many different groups working in the space with varied degrees of coordination, experience, and skill. Most devices portrayed in these stories are actually of extremely limited functionality and are not built of materials as robust as traditional prosthetic construction materials. Though ECF has consistently attempted to de-escalate the increasingly bold claims of cost and performance, these more nuanced stories are less exciting and the media tends veer away from the accurate and toward the sensational. With this in mind, we caution against forming strong opinions based on these stories instead of first hand experience. Beyond the media hype, there is real and exciting work in this space.

3D Printed Devices Thus Far

The amateur construction of 3D printed assistive devices really took off in 2013 with the formation of the e-NABLE Google Plus community, a private forum for 3D printing enthusiasts and the families of limb differences to socialize and compare notes and ideas. For the most part, the community has developed partial hand devices with a focus on congenital limb
differences such as Amniotic Band Syndrome. Over the past year, several devices have been developed for wrist-disarticulation and transradial. When individuals request a device from e-NABLE, they are strongly encouraged to work with an O&P local to them, though it is unclear how many devices are actually fitted under the supervision of an O&P professional. Additionally, it is unclear if there are regular follow-ups after the initial fitting. We suspect that recipients of e-NABLE devices might use the device for a few days and then gradually abandon it, but again, there
is little rigorous data on the subject.

What we do know about the devices is that they have limited physical functionality for ADLs, but as body-powered devices, they facilitate muscle growth (see Dr. Jorge Zuniga’s findings here
<>) with daily use. While physical functionality is not comparable to most conventional upper limb prostheses, most of their utility lies in the social/emotional impact that the devices have on their wearer. The devices tend to be brightly colored and superhero themed, which has the result of
calling attention to the limb difference and celebrating it rather than minimizing the visual impact of the device. Granted, this is a preference that is largely specific to the North American children who form the largest use population of these devices, but it is an interesting trend in what the users of these devices request.

It’s important to note that as a global, decentralized community, each device and story about a device should be treated individually, and not necessarily representative of all work in the space. There are a lot of people who know how to use a 3D printer, but who don’t really know a lot about the work that CPOs do, but nevertheless think that they can replace them. Now that ECF has worked with both 3D printing enthusiasts and with CPOs in e-NABLE, we firmly believe that CPOs will continue to deliver better patient outcomes and are integral to prosthetic care now and in the future.

3D Printers Won’t Replace Prosthetists, They Will Augment Them

3D printers are just tools and as such reflect the skills and intent of the operator. Andreas has worked with e-NABLE for over two and a half years, and has been conducting research in 3D printing since 2011. The key to making 3D printers useful is in the design software that creates the blueprints that the printers turn into real objects.

Jeff and Andreas recently traveled to Haiti as part of a program that ECF and a partner organization, Enable International Haiti, was running with a clinic in Port-au-Prince. Jeff performed a field evaluation of a patient, took a mold of her residual limb (40% transhumeral), and captured a 3D scan of her residual limb. During his physical examination, he discovered a very sensitive neuroma at the site of the amputation, which was a result of the 2010 earthquake. Jeff used this knowledge of the patient’s specific anatomy in combination with his fluency with 3D scanning and 3D printing workflows to produce a comfortable and functional device for the patient (using a conventionally formed polypropylene socket). Without a prosthetist’s experience and knowledge of human anatomy after traumatic amputations, an enthusiast with a 3D scanner and 3D printer would not have been able to produce a successful outcome for this patient.

That being said, there is tremendous potential for 3D printing to be of use to prosthetists and orthotists. There are many advances in materials science, software workflows, and machine reliability that are necessary before the technology can become part of an standard workflows, but these advances are occurring at an ever-accelerating pace.

ECF’s Position and Role

ECF believes that prosthetists should be an integral part of these early explorations of 3D printing’s potential role in the O&P field. We are working closely with prosthetists in the US and abroad to develop workflows and specific devices that address local patients needs. We see 3D printing as an opportunity to address more and more specific patient needs that might not be well-served by components or devices produced by conventional means.

ECF would like to collaborate more closely with members of the O&P field, both to learn more about the needs and concerns of care providers and to educate CPOs about the capabilities and applications of 3D printing technology. This Fall, Jeff Erenstone, Create Prosthetics staff and ECF volunteers will be running a 3D printing workshop at the AOPA National Assembly in Boston. We would like to invite everyone of you to come to this workshop and learn more about 3D printing/additive manufacturing technology and to learn how it might be of use in your practice.

Jeff Erenstone CPO
Mountain O and P Services
7 Old Military Road
Lake Placid NY 12946

Cite this article:
Wolf Schweitzer: - Normalizing prosthetic arms and media: the role of 3D printing - official statement; published 07/07/2016, 18:59; URL:

BibTeX: @MISC{schweitzer_wolf_1631988445, author = {Wolf Schweitzer}, title = {{ - Normalizing prosthetic arms and media: the role of 3D printing - official statement}}, month = {July}, year = {2016}, url = {} }