500 Section - Application of a 3D-Printed Writing–Typing Assistive Device in Patients with Cervical Spinal Cord Injury

A 73-year-old man (AIS A, C6), 46-year-old man (AIS A, C7), and 34-year-old man (AIS A, C5) with chronic cervical spinal cord injury presented with severe hand dysfunction that prevented independent writing and significantly limited typing ability. All patients had weak grasp strength and marked hand muscle atrophy, making it difficult to use commercially available prefabricated assistive devices.

Case Description: To improve hand function, customized 3D-printed writing and typing devices were developed. Hand shapes were scanned with a 3D scanner, converted into STL files, and designed using CAD software. Early PLA-type rigid prototypes were tested but showed poor usability due to limited hand strength, difficulty maintaining pronation, and discomfort. A soft silicone-based device was then produced using a 3D-printed frame and individualized hand measurements.
Patients used the device for 4 weeks. Writing and typing performance were evaluated using the Korean Western Aphasia Battery writing section and a standardized Korean typing program measuring time, accuracy, and errors.

Discussions: Customized silicone devices allowed patients who were unable to write to perform writing tasks for the first time, with improvements in accuracy and functional independence. Patients 2 and 3 demonstrated improved typing accuracy, though speed varied depending on individual adaptation. Subjective satisfaction was high because of comfort, light weight, and ease of use during ADL. The ability to customize devices based on digital scanning and 3D printing enabled better fit than prefabricated aids. Limitations include small sample size, short adaptation period, and lack of long-term follow-up or standardized satisfaction scoring.

Conclusions: Customized 3D-printed writing and typing devices may enhance functional independence in patients with cervical SCI and severe hand dysfunction. This approach offers a low-cost, adaptable alternative to conventional prefabricated orthoses and shows potential for wider clinical application.