Adam Goodworth’s research focus is in the area of human balance control. The overall goal of his work is to use experimentation and mathematical modeling to enhance balance rehabilitation procedures and devices. Reducing falls is a major priority due to the morbidity and mortality associated with falling. To stand up in a variety of contexts, humans must use information from multiple sensory systems to generate muscle activations to counteract gravitational forces and interactions torques between body segments.
To understand sensory integration, mathematical models are incorporated in the Balance Research Laboratory in the College of Education, Nursing and Health Professions (see below). These models represent physiological systems in a simplified manner so that general principles underlying balance control can be ascertained in healthy and pathological populations. The models represent feedback from the visual, vestibular, and proprioceptive sensory systems in conjunction with biomechanical properties of the body. The modeling studies are performed in collaboration with Oregon Health & Science University.
Left: Example model of multi-link balance control system. Passive mechanisms generate torque with no time delay based on biomechanics properties of the musculoskeletal system and active mechanisms generate torque based on sensory feedback from visual, vestibular, and proprioceptive systems.Figure from Journal Neurophysiology, Goodworth and Peterka, 2012.
Principles of balance control are also studied using experiments on campus and at collaborating sites. At the University, numerous methods for assessing balance are incorporated, including dynamic gait. Dynamic gait is investigated in the Balance Lab with a rotating treadmill whereby quick rotations of the treadmill evoke balance responses while participants are walking. This system is currently used to determine how various orthotic devices influence balance during unperturbed and perturbed gait. Body movements are captured via sensors and muscle activations are measured with surface electromyography. Data is analyzed via standard gait variables (e.g., cadence, sway, etc.) and engineering-based methods such as frequency domain analyses. His balance-related research also includes collaborations with Saint Francis Hospital and Medical Center and Harvard-MIT Health Sciences and Technology.
Right: Treadmill that can rotate. Quick rotates evoke balance responses while participants walk. Responses are recorded with sensors and analyzed with custom programs to quantify balance during dynamic walking conditions.