Biomechanical Plasticity In Locomotion with Age, Obesity and Osteoarthritis

Wednesday, March 29, 2017

2:30pm - 3:45pm


115 Goodwin Hall

Dr. Paul DeVita, Kevin P. Granata Memorial Seminar Speaker
Department of Kinesiology
East Carolina University

Abstract: 

Human locomotion is produced through a complex interaction of precise muscle forces that produce appropriate moments around our joints. These moments rotate our body segments through particular ranges of motion at particular times in the healthy gait cycle. This skilful control of muscle forces produces the stereotypical sequence of maximum joint moments from proximal hip joint to distal ankle joint. Thus the magnitude and the timing of muscle forces and joint moments are fundamental to successful and safe locomotion. In contrast, adaptations in muscle forces and joint moments are often observed in individuals with compromised health states. We have termed these adaptations, biomechanical plasticity and they represent a neuromuscular response necessary to produce locomotion with an altered musculoskeletal system. Biomechanical plasticity alters the relative contributions made by each muscle to the overall mechanical output necessary to walk and it has been observed in a variety of populations including both healthy and frail older adults, Class III obese adults, and adults with OA. Healthy, older adults walk with a distal to proximal shift in muscle function. They increase the mechanical output at their hips and reduced the output at the ankle. Increased frailty in older adults appears to promote a greater shift towards the hip however, this plasticity has not been fully verified. Interestingly, biomechanical plasticity is not observed in obese adults with BMIs ~35 kg/m2 but only in much heavier individuals. Their plasticity is in the opposite direction and emphasizes increased ankle muscle and joint function. Thus the interaction of age and obesity presents locomotion challenges for older, heavier people through competing biomechanical plasticity pathways. OA also induces a plastic response in locomotion and the magnitude of the response is related to the severity of OA. Biomechanical plasticity in knee OA is similar to that in older adults with increased hip joint and muscle function compensating for reduced knee joint and muscle function and the magnitude of this shift increases with greater joint deterioration. The stimuli producing the plastic response however is certainly different between these groups with pain inducing the change in OA and as yet unidentified physiological changes with age inducing plasticity in older adults. We will explore biomechanical plasticity as a viable and necessary process that enables various populations to maintain locomotion capacity in the presence of altered health status. Also, I have a few other fun ditties thrown in. 

Biography: 

It was obvious to Dr. Paul DeVita that he was destined to become a locomotion biomechanist when in 1967 while sitting in 7th grade German glass and gazing out the window as would most future scientists, most future non-scientists and, let’s face it, practically any 7th grade German student, he marveled at how he recognized Matty Rossoff far in the distance by the way he walked. All the rest is secondary, however, Dr. DeVita graduated from the Department of Biology, State University of New York at Binghamton with a B.A. in 1977. He later received his M.S. (1984) and Ph.D. (1986) degrees in Biomechanics from the Department of Physical Education and Human Movement Science at the University of Oregon. Dr. DeVita has been on the faculty of the Department of Kinesiology, East Carolina University in Greenville, NC since 1995. He currently holds one of two Leroy T. Walker Distinguished Professorships in the College of Health and Human Performance and he is Past-President of the American Society of Biomechanics. Dr. DeVita has received research funding from the National Institutes of Health, the National Athletic Trainers’ Association, the Department of Defense, and the North Carolina Institute on Aging, among other organizations. Dr. DeVita has investigated biomechanics of human locomotion for the past 30 years and has concentrated on neuromuscular adaptations, i.e. biomechanical plasticity, in several populations including older adults, adults with knee osteoarthritis, and obese adults. Dr. DeVita is on the Editorial Boards of Exercise and Sport Science Reviews and the Journal of Biomechanics and he reviews grants for the MRS Study Section of NIH. He is a member and Fellow of the American Society of Biomechanics, the American College of Sports Medicine, and the National Academy of Kinesiology and he is a member of the International Society of Biomechanics. Dr. DeVita is the creator of National Biomechanics Day and he invites everyone to participate in this exciting and fun event. He is pretty good at ping pong, says some funny things now and then, and seems to be the only professor around who prominently displays his high school but no other diploma, named after the important biomechanist himself, Walt Whitman.