Grant: Discovery Grants Program - Individual

Musculoskeletal disorders are the single most common reason why people miss work. While our understanding of specific work features that contribute to fatigue and injury (such as postures, force requirements and repetition) has improved in recent years, the prevalence of work-related upper extremity disorders remains troubling. How humans interact with tools and objects are critical aspects of both work and daily life. The neuromuscular system has a complex, but fascinating, arrangement of muscles which allows for smooth movement and precision. For example, simple tasks such as grasping a door handle or manipulating a tool requires a combination of coordinated events from the brain to control wrist motion and hand gripping. How humans control muscular responses to complete such tasks are largely unknown. This proposal works on the premise that, to have a substantial impact on musculoskeletal disorders, we must first improve our fundamental understanding of basic hand function. The overall goal of this research program is to clarify how the nervous and musculoskeletal systems control hand movements and force production. This will be accomplished by using an interdisciplinary approach that combines experimental techniques from biomechanics, robotics, and neurophysiology. This proposal will contribute to the research goals by evaluating how biomechanics, sex, and anthropometrics influence forearm muscle activity during work related tasks. The first objective will clarify the role of biomechanics and anthropometrics in muscle recruitment for hand control that includes simultaneous wrist actions and gripping. Using a wrist robot, external force demands will be experimentally manipulated to better understanding unique muscle contributions. Given that performance of industrial tasks must be maintained in the presence of fatigue, the second objective will explore neuromuscular compensation strategies when a muscle(s) has impaired function and other muscles need to adapt for task completion. This objective will be completed in a unique way, using a robotic device and electrical stimulation to isolate and fatigue individual muscles. Using an experimental design that simulates tool use and workplace demands, this program of research will deliver an improved understanding of forearm muscle function for hand control. The outcomes from this interdisciplinary approach will advance knowledge and fill important gaps in discovering relationships amid neural control and biomechanics. This research can have industrial importance leading to improved human factors and ergonomics for tool design. The outcomes will also provide valuable insight for future workplaces looking to improve human-robot interaction. This research program offers a pathway for optimizing human performance which can impact quality of life for all working Canadians.