Creating 3D Printed Assistive Technology Through Design Shortcuts: Leveraging Digital Fabrication Services to Incorporate 3D Printing into the Physical Therapy Classroom
Erin Higgins, William Berkley Easley, Karen L. Gordes, Amy Hurst, Foad Hamidi · 2022 · Proceedings of the 24th International ACM SIGACCESS Conference on Computers and Accessibility (ASSETS) · doi:10.1145/3517428.3544816
Summary
This paper investigates how to integrate 3D printing into physical therapy (PT) education without requiring PT students to become experts in CAD or digital fabrication. Previous research showed that while 3D printing has great potential for creating customized assistive technology, the technical skills required — particularly CAD modeling — present a significant barrier for clinicians. The researchers designed a six-session educational series embedded across two semesters of a graduate PT curriculum at the University of Maryland, involving 58 PT students. The key innovation was connecting PT students with professional makers at a youth-staffed community makerspace (Digital Harbor Foundation) rather than teaching students to use 3D printing tools directly. In Phase 1 (sessions 1-4), students learned about AT and 3D printing concepts, then designed devices for 5 simulated end users using paper order forms, sketches, and clay models that were sent to the makerspace for fabrication. In Phase 2 (sessions 5-6), students applied their skills to design AT for 12 real volunteer end users with conditions including stroke, decreased grip strength, cerebral palsy, and collapsed arches. The devices created included custom pen grips, wrist splints, finger extension aids, utensil holders, shoe inserts, and walker attachments, all constrained to a maximum 5x5x5-inch size printable on consumer-grade 3D printers using PLA and NinjaFlex filaments.
Key findings
All 19 AT devices (5 simulated, 14 real) were successfully created, though most required small modifications — primarily to attachment mechanisms and surface smoothness. PT students's existing sketching skills proved to be a major asset, as they could produce detailed technical drawings with precise measurements that makers could interpret. Clay modeling was effective for smaller objects like pen grips but problematic for larger ones, as clay deformed and shrank during drying, leading to dimensional inaccuracies. The biggest challenge was communication between PT students and makers: without face-to-face interaction or shared technical language, paper order forms alone were insufficient. Students struggled to specify details in ways makers could interpret — for example, one group listed finger hole diameters in centimeters rather than the requested millimeters and failed to specify inner vs. outer diameter, resulting in holes that were too small. Working with real end users was dramatically more motivating than simulated cases, but raised heightened concerns about safety and liability. Students noted a fundamental tension between the iterative nature of 3D printing design and the time-pressured, insurance-driven realities of clinical PT practice where repeated patient visits for design iterations are impractical. PT students were willing to pay a median of for a custom device and wait a median of 168 hours for fabrication. Many students felt 3D printing was best suited for small additions to existing commercial AT devices rather than creating devices from scratch.
Relevance
This research offers a practical model for how healthcare professionals can leverage digital fabrication for custom assistive technology without needing to become engineers. The "design shortcut" approach — connecting clinicians who understand patient needs with makers who have fabrication expertise — is replicable in any setting where makerspaces or fabrication services exist near clinical training programs. For accessibility practitioners, the communication challenges documented here are instructive: developing a shared vocabulary between clinical and technical domains is essential and non-trivial. The finding that 3D printing works best as an augmentation to existing commercial AT (adding custom grips, extensions, or attachments) rather than creating devices from scratch provides practical guidance for organizations exploring digital fabrication. The liability concerns raised by students — who is responsible if a 3D-printed device breaks and injures a patient? — remain an unresolved barrier to wider clinical adoption that the field needs to address.
Tags: 3D printing · assistive technology · digital fabrication · physical therapy · education · makerspaces · co-design · DIY assistive technology · interdisciplinary collaboration