An evaluation of 3D printable elastics for post stroke dynamic hand bracing: a pilot study

Area of Science:

• Biomedical Engineering
• Rehabilitation Science
• Materials Science

Background:

• 3D printing (3DP) offers customization for rehabilitation devices.
• 3DP elastic materials enable novel dynamic orthoses.
• Stroke survivors often require upper extremity functional support.

Purpose of the Study:

• To explore the feasibility of using 3DP elastic materials for dynamic hand orthoses.
• To evaluate the usability and functional impact of these orthoses in stroke survivors.

Main Methods:

• A dynamic hand orthosis with replaceable finger components was fabricated using 3DP elastic materials of varying stiffness.
• Five stroke survivors with moderate hand impairment participated in the study.
• Usability, upper extremity function, and biomechanics were assessed and compared to a commercial orthosis.

Main Results:

• No significant usability differences were found between 3D-printed and commercial orthoses.
• Increased stiffness of 3DP materials significantly reduced pincer force and the Box and Blocks Test (BBT) score.
• The commercial orthosis showed a clinically significant reduction in BBT score but did not affect pincer force.

Conclusions:

• Dynamic hand orthoses fabricated with 3DP elastic materials are a feasible clinical application.
• Material stiffness is a critical factor influencing functional outcomes in 3DP orthoses.
• Further research is warranted to optimize 3DP orthosis design for stroke rehabilitation.