• Goeran Fiedler Department of Rehabilitation Science and Technology, University of Pittsburgh, Pennsylvania, USA.
  • Saiph Savage Human Computer Interaction Lab, Computer Science and Electrical Engineering Department, West Virginia University, Morgantown, WV, USA.
  • Jon Schull e-NABLE, Rochester Enable Limited, Rochester NY
  • Jennifer Mankoff Allen School of Computer Science & Engineering, University of Washington, Seattle, WA, USA.
Keywords: Prosthetics, 3D-printing, e-NABLE, Upper limb prosthetic, Low-cost prosthetic, Amputee, Rehabilitation


Professional Opinion
The emergence of 3D-printed upper limb prosthetic devices a couple of years ago, spearheaded substantially by the e-NABLE community (1, 2), has triggered a variety of reactions, ranging from euphoric press coverage predicting a new age of low-cost universally obtainable prosthetic solutions to anxious reluctance by clinicians fearing the demise of high-quality professional health care provision (3, 4). The circumstance that untrained volunteers produce e-NABLE devices on their hobby-grade 3D-printers (5) was both hailed as a revolutionary paradigm shift suited to address a host of current challenges in health care economics, and derided as inappropriate intrusion into long-standing training and certification standards of a well-regulated profession. That many of the early generation e-NABLE devices targeted young patients with partial hand amputation (6) was interpreted by proponents as finally offering this neglected population long-desired solutions, whereas skeptics felt that many of the recipients of such devices would traditionally have been deemed to have a residual functional enough to be a contra-indication for a prosthesis (7).

So, how valuable are those 3D-printed devices really for their users, and – be extension – for society at large? Most reasonable people may feel that the truth, as for so many contested questions, is somewhere in the middle. The confidence boost from having a 3D printed superhero hand can be very real for a young patient, even if it is used only for short times. Affordable customizations tailored to special tasks, such as holding a musical instrument (8), can make a big difference for young users, even if there is little utility beyond that. Meanwhile, the e-NABLE community has progressed to be about more than mere device fabrication and distribution, with EnablewebCentral having become a sophisticated platform for tracking cases, recruiting follow up feedback, and even providing referrals to and coaching from Prosthetists.

That devices produced by hobbyists would be able to outright replace much more expensive commercial prostheses is no longer being claimed by representatives of the e-NABLE community. Instead, a mutually beneficial collaboration between the 3D-printing community and Prosthetics and Orthotics (P&O) professionals has been proposed (9). News stories on the topic have recently become fewer and less sensationalist. On the other side, many prosthetics clinicians have come to realize that 3D-printing technology does have the potential to substantially change fabrication methods in the field, and that there is good reason to embrace the associated technological progress. It can be argued that the development already has brought some benefits for the field:
• The publicity, even if partly unwarranted, may have triggered a greater interest in the P&O profession, attracting more talented students, and motivating new research opportunities.
• Some of the young patients who have been introduced to prosthetics through an, even unnecessary, e-NABLE device may be more likely to accept and use prostheses later on.
• Limb loss management being the first prominent area of using crowd intelligence to address healthcare challenges (10), an approach that promises wide applicability in the future (11, 12), gives our field once more a pioneering role within the allied health sciences.
Still, while it may be easy to intuitively agree with many of those points, there is very little actual evidence on the underlying question of how effective 3D-printed upper extremity devices are in achieving their intended purposes. Most of the research that has been published on the topic to date is limited to technical description and basic function testing of devices. There appears to be no pertinent outcome data of any kind for 3D-printed e-NABLE devices, let alone data that would allow comparison to conventional prosthetics.
This gap can be addressed. The field of P&O has come a long way in establishing evidence based decision making. As new technology has been introduced in increasing frequency over recent decades, the necessity to demonstrate its benefits have yielded more and better research studies. Outcome assessment, as a key component of Evidence Based Practice, has rightfully become more and more important in the field over the past years. A great many different tools have been developed and are now available to allow for reliable data on most any conceivable assessment criterion. Much important work has been - and continues to be – done to determine validity of the various tools in different populations (13). While the availability of specialized outcome assessment tools is a benefit for the primary clinical purposes of documenting and monitoring individual patients’ rehabilitation progress, the respective data can – with limitations – also be useful to compare different interventions. Certainly, this falls short of the scientific rigor of a prospective study with randomized group allocation, but, with a sufficiently large response rate, can deliver relevant descriptions of real-life outcomes to allow fact-based answers to our question and to inform future work.

A group of researchers and clinicians led by Jen Mankoff (University of Washington) and Jon Schull (e-NABLE) is pursuing this approach. Having devised a comprehensive online questionnaire, efforts are currently focused on collecting a sufficient number of responses from both users of e-NABLE devices and conventional upper limb prostheses (14). This will allow a detailed, evidence-based, comparison between those device groups on a shared scale. As is common in prosthetics research in general, and in particular if targeting an upper limb loss population, it is a major challenge to obtain a large enough sample size to allow for generalizable conclusions. To address this issue, the survey has been translated into several foreign languages and is being advertised through a number of online and offline media.

If it generates sound evidence on the effective differences between upper limb device classes, the respective discussion will become less biased and more constructive. Given the recent developments in the field and the expanding device options for people with limb loss, it would be dangerous to assume that nothing new can be learned from such data. Knowing what today’s patients want (or don’t want) and knowing what works (or doesn’t work) for them is important, not just for makers of 3D-printed devices but for trained prosthetists as well. Clearly, data-based innovation in prosthetic care is accelerating. With the participation of traditional clinicians, professional prosthetic services could both benefit and contribute.

1. Tanaka KS, Lightdale-Miric N. Advances in 3D-printed pediatric prostheses for upper extremity differences. The Journal of Bone and Joint Surgery. 2016; 98: 1320-6. DOI: 10.2106/JBJS.15.01212
2. Zuniga J, Katsavelis D, Peck J, Stollberg J, Petrykowski M, Carson A, Fernandezet C. Cyborg beast: a low-cost 3d-printed prosthetic hand for children with upper-limb differences. BMC research notes. 2015; 8: 10.
3. Kesselring J, Fiedler G. Prosthetist’s Assessment of Additive Manufacturing as an Alternative to conventional manufacturing techniques in P&O. 42nd Annual AAOP Meeting and Scientific Symposium. Orlando, FL 2016.
4. Hofmann M, Burke J, Pearlman J, Fiedler G, Hess A, Schull J, Hudson S, Mankofet J. Clinical and maker perspectives on the design of assistive technology with rapid prototyping technologies. Proceedings of the 18th International ACM SIGACCESS Conference on Computers and Accessibility. ACM, 2016, p. 251-6. DOI: 10.1145/2982142.2982181
5. Foster KR. 3-Dimensional Printing in Medicine: Hype, Hope, and the Challenge of Personalized Medicine. Philosophy and Engineering. Springer, 2017, p. 211-228.
6.Burn MB, Ta A, Gogola GR. Three-dimensional printing of prosthetic hands for children. The Journal of hand surgery. 2016; 41: e103-e9.
7. James MA, Bagley AM, Brasington K, Lutz C, McConnell S, Molitor F. Impact of prostheses on function and quality of life for children with unilateral congenital below-the-elbow deficiency. The Journal of Bone and Joint Surgery. 2006; 88: 2356-65. DOI: 10.2106/JBJS.E.01146
8. Hofmann M, Harris J, Hudson SE, Mankoff J. Helping hands: Requirements for a prototyping methodology for upper-limb prosthetics users. Proceedings of the 2016 CHI Conference on Human Factors in Computing Systems. ACM, 2016, p. 1769-80. DOI: 10.1145/2858036.2858340
9. Schull J. Toward Collaboration: The 3D-Printing Community and O&P Professionals The O&P EDGE. 2015, p. 88. [Available at:] Accessed August 5. 2018.
10. Schull J. Enabling the future: Crowdsourced 3D-printed prostheticsas a model for open source assistive TechnologyInnovation and mutual aid. Proceedings of the 17th International ACM SIGACCESS Conference on Computers & Accessibility. ACM, 2015, p. 1.
11. Gleason C, Ahmetovic D, Savage S, Toxtli C, Posthuma C, Asakawa C, Kitani KM, Bigham JP. Crowdsourcing the Installation and Maintenance of Indoor Localization Infrastructure to Support Blind Navigation. Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies. 2018; 2: 9. [Available at:] Accessed August 5. 2018.
12. Savage S, Monroy-Hernandez A, Höllerer T. Botivist: Calling volunteers to action using online bots. Proceedings of the 19th ACM Conference on Computer-Supported Cooperative Work & Social Computing. ACM, 2016, p. 813-22.
13. Lindner HY, Nätterlund BS, Hermansson LMN. Upper limb prosthetic outcome measures: review and content comparison based on International Classification of Functioning, Disability and Health. Prosthetics and orthotics international. 2010; 34: 109-28. DOI/pdf/10.3109/03093641003776976.
14. Mankoff J, Savage S, Eckert S, Ngo C, Fiedler G. User experiences with traditional and 3D-printed Upper Extremity Prostheses, Development of a comprehensive Survey Instrument. American Orthotic and Prosthetic Association (AOPA) Assembly. Vancouver, BC, 2018.

Article PDF file:

Author Biographies

Goeran Fiedler, Department of Rehabilitation Science and Technology, University of Pittsburgh, Pennsylvania, USA.

Dr. Goeran Fiedler, is a credentialed prosthetist and orthotist, who holds additional graduate degrees in Clinical Engineering and Health Sciences. He has worked as a clinician and later researcher in the field of P&O for more than 25 years, and currently serves as Assistant Professor in the Master of Science Prosthetics & Orthotics program at the University of Pittsburgh. His research interests are in assessing and improving prosthesis utilization, alignment, and prescription.

Saiph Savage, Human Computer Interaction Lab, Computer Science and Electrical Engineering Department, West Virginia University, Morgantown, WV, USA.

Dr. Saiph Savage is an Assistant Professor of Computer Science at West Virginia University (WVU) where she directs the Human Computer Interaction Laboratory (HCI @ WVU Lab). She is also a visiting professor at the Human-Computer Interaction Institute at Carnegie Mellon University (CMU), a J. Wayne and Kathy Richards Faculty Scholar, and adjunct professor at the National Autonomous University of Mexico (UNAM). Her research in Social Computing and Crowdsourcing focuses on the design of systems that spark better coordination of volunteers and empower communities to reach more complex goals.

Jon Schull, e-NABLE, Rochester Enable Limited, Rochester NY

Dr. Jon Schull, Founder of e-NABLE: Volunteers designing and delivering free 3D-printed prosthetics worldwide. A biological psychologist, inventor, entrepreneur, human-computer interaction researcher, and digital community organizer, Dr. Jon Schull is the creator of e-NABLE, an online philanthropic community that designs, customizes and fabricates open-sourced affordable 3D-printed prosthetic hands and arms for children and adults with upper limb differences. In past lives, Schull was founder of aka DigitalGoods (NASDAQ:DIGS) a seminal digital rights management company, professor and former director of the Center for Student Innovation at Rochester Institute of Technology. His current base of operations is the Rochester Enable Lab at Vertus High School.

Jennifer Mankoff, Allen School of Computer Science & Engineering, University of Washington, Seattle, WA, USA.

Dr. Jennifer Mankoff is the Richard E. Ladner Professor in the Paul G. Allen School at the University of Washington. She earned her B.A. at Oberlin College and her Ph.D. in Computer Science at the Georgia Institute of Technology. Her research focuses on assistive technology for access, health and wellness, and takes a multifaceted approach that includes machine learning, 3D printing, and tool building. Her research has been supported by Google Inc., the Intel Corporation, IBM, Hewlett Packard, Microsoft Corporation, and the National Science Foundation. She was awarded the Sloan Fellowship and the IBM Faculty Fellowship.

How to Cite
G. Fiedler, S. Savage, J. Schull, and J. Mankoff, “THE CASE FOR BROAD-RANGE OUTCOME ASSESSMENT ACROSS UPPER LIMB DEVICE CLASSES”, Canadian Prosthetics & Orthotics Journal, vol. 1, no. 1, Aug. 2018.