Development of a Modular Thumb Support with Multi-Directional Locking to Improve Post-Stroke Thumb Opening and Positioning
Faculty Mentor Information
Dr. Joel Perry, University of Idaho
Presentation Date
7-2025
Abstract
Stroke is a leading cause of long-term adult disability and frequently impairs voluntary control of the hand. Disruption to the brain’s motor pathways weakens the muscles responsible for finger extension while also increasing involuntary tone in the finger flexors. This imbalance makes it difficult to extend or release the hand, hindering daily activities and slowing rehabilitation. Although dysfunction affects the entire upper limb, effective thumb positioning—particularly in abduction, extension, and opposition—is essential for functional hand use. Most orthotic devices focus on supporting grasp but offer little assistance for controlled hand opening or repeatable thumb positioning. To address this gap, a modular thumb support attachment was developed for a lab-designed hand orthosis. The design includes a multi-layered spherical joint with a position-locking cam handle, allowing for manual locking and multi-directional adjustment. The attachment was designed to align with natural thumb movement and provide support for abduction and extension without interfering with grasp. It remains low-profile and lightweight for user comfort and integrates directly into the existing hand orthosis framework. Preliminary self-testing demonstrated improved comfort, positioning, and ease of use during repeated motions. This early-stage prototype presents a promising direction for adaptable, user-centered orthotic tools that support functional hand rehabilitation.
Development of a Modular Thumb Support with Multi-Directional Locking to Improve Post-Stroke Thumb Opening and Positioning
Stroke is a leading cause of long-term adult disability and frequently impairs voluntary control of the hand. Disruption to the brain’s motor pathways weakens the muscles responsible for finger extension while also increasing involuntary tone in the finger flexors. This imbalance makes it difficult to extend or release the hand, hindering daily activities and slowing rehabilitation. Although dysfunction affects the entire upper limb, effective thumb positioning—particularly in abduction, extension, and opposition—is essential for functional hand use. Most orthotic devices focus on supporting grasp but offer little assistance for controlled hand opening or repeatable thumb positioning. To address this gap, a modular thumb support attachment was developed for a lab-designed hand orthosis. The design includes a multi-layered spherical joint with a position-locking cam handle, allowing for manual locking and multi-directional adjustment. The attachment was designed to align with natural thumb movement and provide support for abduction and extension without interfering with grasp. It remains low-profile and lightweight for user comfort and integrates directly into the existing hand orthosis framework. Preliminary self-testing demonstrated improved comfort, positioning, and ease of use during repeated motions. This early-stage prototype presents a promising direction for adaptable, user-centered orthotic tools that support functional hand rehabilitation.