Development of an Affordable Self-Stretching Passive Device for Treatment and Assessment of Spastic Wrist and Fingers Post-Stroke

Stroke, a condition in which blood flow has been restricted to parts of the brain, has been known to cause spasticity, a condition in which the muscles abnormally tense up through an overactivation of the stretch reflex. One low-cost solution to this problem is the use of self-operated passive stretching devices that can be operated with minimal assistance. The goal of this project was to develop and evaluate a new self-stretching wrist and finger device using an iterative design cycle. The device was designed with the following two stretching mechanisms: a rotating dial and an inflatable grip. Three stages of the device prototypes were developed: early, late, and final. After each stage, a usability survey was conducted with a group of healthy controls to rate 0-10 in criteria of overall comfort, unexpected pain, upper arm muscle tension, and device security of the arm. After, design changes were made to address common feedback. In the end, we saw that prioritizing the reduction of pain, decrease of unnecessary upper arm muscle tension, and increase of device security of the arm proved to be valuable measures of increasing overall device comfort. In addition, electromyography (EMG) data was collected with a healthy control subject to verify that the device was able to properly initiate the wrist flexors and extensors through the flexion and extension movement, and that each muscle group was isolated properly to their respective movements through the device.