LCSR Seminar: Kyle Reed “Asymmetries in Symmetric Human Motions and Rehabilitation”
This presentation will discuss how symmetric and asymmetric motions can be used for training and rehabilitation. Many daily tasks require that a person use both hands simultaneously, such as moving a large book or opening the lid on a jar. Such bimanual tasks are difficult for people who have a stroke, but the tight neural coupling across the body has been hypothesized to allow individuals to self-rehabilitate by physically coupling their hands. The interaction discussed here separates the task and guidance forces by guiding one hand so the user can actively recreate the motion with their other hand that receives task-related forces. This method is based on the ability of humans to easily move their hands through similar paths, such as drawing circles, compared to the difficulty of simultaneously drawing a square with one hand and a circle with the other. Experiments were performed to characterize the reference frames, interaction stiffnesses, and trajectories that humans can recreate.
The second half of this presentation will focus on gait rehabilitation for individuals with asymmetric impairments. Asymmetric gait is caused by many impairments, such as leg-length discrepancy, prosthetics, and stroke. Using a model of gait based on kinematic synchronization, it is shown that some types of symmetry can be generated in a person with an asymmetric impairment, but not simultaneously in both motions and forces. To balance the limitation of always having some asymmetries, perception of gait is used to put limits upon what appears symmetric even if it is not perfectly symmetric. One rehabilitation method, the Gait Enhancing Mobile Shoe (GEMS), uses an exaggerated asymmetric motion to generate an after-effect that has a better walking pattern. The GEMS uses a Kinetic Shape wheel to passively redirect the user’s natural downward forces while walking into a backward motion that generates a corrective after-effect. The Kinetic Shape has also been applied to the tip of a walking crutch to assist in locomotion. At the conclusion of this talk, you should have a better understanding of the symmetries and asymmetries that exist in your daily motions.
Dr. Kyle Reed is an Associate Professor in the Department of Mechanical Engineering at the University of South Florida. He was a Post-Doctoral Scholar in the Laboratory for Computational Sensing and Robotics at Johns Hopkins University from 2007-2009. He received his PhD from Northwestern University in 2007 and B.S. from the University of Tennessee in 2001, all in Mechanical Engineering. He has received funding from NSF, NIH, Florida High Tech Corridor, and industry. His research interests are in medical/rehabilitation robotics and human-centered robotics, which include designing intuitive and cooperative devices that interact with humans, as well as engineering education. More information about Dr. Reed and his research can be found at http://reedlab.eng.usf.edu