Quantifying and Rehabilitating Fine Sensorimotor Hand Function in Stroke Patients Using an Instrumented Fragile Object

/ABSTRACT Stroke is a leading cause of long-term disability worldwide and 80% of all stroke survivors experience upper-limb hemiparesis (i.e., weakening of motor control in the hand and arm on one side)1. Upwards of 50% of individuals with upper-limb hemiparesis also experience tactile sensory deficits in the hand2–4. However, tactile sensory deficits and the fine sensorimotor function that stems from tactile sensory feedback are frequently overlooked in today’s rehabilitation programs5,6. This is despite research indicating that the integration of both sensory and motor training can be more effective than conventional approaches which focus primarily on motor7. This neglect of fine sensorimotor function can be explained in part due to a lack of standardized assessments, rehabilitation tools, and validated performance metrics5,8. Given the importance of fine sensorimotor hand function in daily life, there exists a critical need for a standardized device capable of both assessing and rehabilitating fine sensorimotor hand function. Practicing grip force regulation, as one would do when handling a fragile object, presents a novel and unique method to both assess and rehabilitate fine sensorimotor hand function, as grip force regulation relies heavily on tactile feedback and fine motor control9,10. To assess and rehabilitate fine sensorimotor hand function after stroke, we are developing the Electronic Grip Gauge (EGG), a handheld wireless device that can mimic a fragile object. The EGG consists of a 3D-printed block embedded with sensors that track applied grip force, load force, acceleration, and relative object position. Stroke patients attempt to transfer the EGG over a barrier as quickly as possible while also regulating their grip force to avoid “breaking” the object. If applied grip force exceeds a set threshold, then an audible “break” sound plays. As a fine sensorimotor assessment, one must rely on their underlying tactile feedback to monitor and regulate their fine motor execution during transfers. The objective of this proposal is to validate the EGG as a diagnostic and rehabilitative tool for fine sensorimotor function, and to demonstrate performance marker reliability in stroke populations. Our central hypothesis is that an individual’s ability to rapidly transfer fragile objects without breaking them can provide quantifiable performance metrics for fine sensorimotor function. This application outlines a rigorous scientific and clinical training plan at the University of Utah Neurorobotics Lab which is housed within the Craig H. Neilsen Rehabilitation Hospital. Mentorship from leaders in stroke rehabilitation and clinical trials research will be combined with longitudinal clinical experiences in the Department of Physical Medicine and Rehabilitation. These activities will enable the applicant to become a successful physician-scientist in physical medicine and rehabilitation with a focus on running a future lab dedicated to the development and translation of novel rehabilitation devices. Project Number: 1F30HD117488-01A1 | Fiscal Year: 2025 | NIH Institute/Center: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) | Principal Investigator: Michael Adkins | Institution: UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH, SALT LAKE CITY, UT | Award Amount: $54,538 | Activity Code: F30 | Study Section: Special Emphasis Panel[ZRG1 F03B-B (20)] View on NIH RePORTER: https://reporter.nih.gov/project-details/1F30HD11748801A1