Dr. Lori A. Vallis
Associate Professor
Email: lvallis@uoguelph.ca
Office: ANNU 343
Ext: 54589
Lab: ANNU 208
Ext: 54166
Profile | Education | Research | Publications | Teaching | Grad Students | Links |
Profile
My involvement in an elective fourth year undergraduate biomechanics research project first opened my eyes to the fact that biomechanics is much more than just applied physics! This experience taught me that the field of biomechanics uses a multidisciplinary approach to study the effects and control of forces that act on and are produced by living beings. Ideas and concepts from diverse fields of study including anatomy, physiology, neuroscience, physics, and engineering, are used to this purpose. This multifaceted approach to the study of human movement appeals to me as strongly today as it did when I was undergraduate kinesiology student.
Education
B.Sc. - Ottawa University
M.Sc. - Ottawa University
Ph.D. - University of Waterloo
Research
Sensory information is critical for the formation of internal representations of our bodies and the external world. These representations are subsequently used to guide our movements; in fact, purposeful action is possible because the central nervous system is capable of integrating control of the motor system with available sensory information about body position in space. Although there are indications in the literature that at different stages in life, e.g. childhood, old age, there is a shift in the role of various sensory inputs for locomotor control, there is little basic scientific evidence to support this theory. Additional fundamental knowledge is necessary to fully understand the complex relationship between sensory input and executed adaptive locomotor strategies across the lifespan. I pursue three areas of inquiry in my research program including: elderly individuals, a healthy young adult population and children.
Elderly individuals
This area of my research is timely and of critical importance due to the rising number of aging baby-boomers in Canada and the financial impact that falls in the elderly has on the national health care system. I have concentrated most of my research efforts over the past few years in this area of my research program.
Healthy young adult population
I am specifically interested in understanding how sensory information is used by members of a young, healthy adult population to complete activities of daily living. To achieve this goal, I probe the role of sensory information in the control of complex locomotor behaviours via a variety of different methods, e.g. placement of obstacles in the travel path, delivery of a head perturbation, delivery of galvanic vestibular stimulation, exposure to altered sensory information in virtual reality environments.
Children
Despite demonstrations of effective locomotor strategies, smooth dynamic and complex inter-segmental coordination strategies have not been previously observed in children during complex locomotor tasks e.g. obstacle avoidance tasks. These observations suggest that the maturation of locomotor control strategies is still developing in mid-childhood. In this area of my research program I probe how children use sensory information to control their locomotor behaviour during complex gait tasks.
Selected Publications
(*indicates graduate student **indicates undergraduate student under Dr. Vallis’ supervision
The role of sensory input and mobility in the elderly
*Lowrey CR, **Watson A and Vallis LA (2007). Age-related changes in avoidance strategies when negotiating single and multiple obstacles. E-pub ahead of print , Experimental Brain Research [ DOI 10/1007/s00221-007-0986-0 ].
*Lowrey CR, Reed RJ and Vallis LA. (2007) Control strategies used by older adults during multiple obstacle avoidance. Gait & Posture, 25(4): 502-8.
**Fuller JR, Adkin AL and Vallis LA. (2007) Strategies used by older adults to change travel direction. Gait & Posture 25(3): 393-400.
*Reed RJ, Lowrey CR and Vallis LA (2005). Middle-old and old-old retirement dwelling adults respond differently to locomotor challenges in cluttered environments. Gait & Posture, 23(4):486-9.
The role of sensory input and mobility in a healthy young adult population
*Reed-Jones RJ, Reed-Jones JG, Trick LM and Vallis LA . Can galvanic vestibular stimulation reduce simulator adaptation syndrome? 4th International Driving Symposium on Human Factors in Driver Assessment, Training, & Vehicle Design (July 2007 in Stevenson, WA, USA). This student paper was the winner of the “Honda Outstanding Student Paper” Award.
*Reed-Jones RJ, Vallis LA, Reed-Jones JG and Trick LM. Postural instability following immersion in a virtual environment driving simulator. Ontario Biomechanics Conference, Barrie ON, February 2007. This student abstract/presentation was the winner of the Canadian Biomechanics Society “Best Biomechanics Paper” Award.
Vallis LA and Patla AE (2004).Expected and unexpected head yaw movements result in different modifications of gait and whole body coordination strategies.Experimental Brain Research. 157(1): 94-110.
Vallis LA and McFadyen BJ. (2003) Locomotor adjustments for circumvention of an obstacle in the travel path. Experimental Brain Research. 152(3):409-14.
Vallis LA, Patla AE and Adkin AL. (2001) Control of steering in the presence of unexpected head movements: Influence on sequencing of sub-tasks. Exp Brain Res. 138(1):128-34.
The role of sensory input and mobility in children
*Berard J and Vallis LA (2006). Characteristics of single and double obstacle avoidance strategies: A comparison between adults and children. Experimental Brain Research , 175 (1): 21-31.
Vallis LA and McFadyen BJ (2005). Children use different anticipatory control strategies than adults to circumvent obstacles in the travel path. Experimental Brain Research. 167(1):119-27.
Teaching
HK*2270 Human Biomechanics
HK*4070 Clinical Biomechanics
Grad Students
E. McIntosh (MSc student)
T. Worden (MSc student)