Dr. Lori Ann Vallis

Phone number: 
ext. 54589 (Office), ext. 54166 (Lab)
ANNU 343
ANNU 273

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.

B.Sc. (Human Kinetics)- University of Ottawa
M.Sc. (Biomechanics) - University of Ottawa
Ph.D. (Kinesiology: Biomechanics) - University of Waterloo
Post-Doctoral Fellow - Université of Laval/Center for Interdisciplinary Research in 
Rehabilitation and Social Integration (CIRRIS) Québec, Canada

Purposeful action requires the central nervous system to integrate, into ongoing movement patterns, available sensory information about body position in space. Vision is a unique sensory input as it provides this information in advance, for route-planning, and the adjustment of on-going stepping strategies. To date, my research program has focused on strategies used to execute safe movement during adapted locomotor tasks (steering, obstacle circumvention, obstacle stepping) and the role of vision in these tasks. 

I am also interested in exploring the impact of cognitive or brain function on locomotor control. The reality is, we routinely perform mental tasks while walking in busy, dynamic environments (e.g. listening to a loudspeaker announcement while walking through a busy shopping mall) and recent research indicates that performing more than one task at a time influences our walking performance. Given the commonness of dual tasking in our daily living, I hope to map patterns of cognitive-locomotor interference for multiple adapted locomotor (e.g. obstacle circumvention) and cognitive activities (e.g. visuo-spatial cognitive tasks) and ascertain optimal training strategies for dual-task performance.

It has been suggested that at different stages in life, there are varying levels of available cognitive resources in addition to shifts in the role of various sensory input in locomotor control, however, there is little basic scientific evidence which examines these shifts over the lifespan. 

For example, young children demonstrate effective locomotor strategies in uncluttered environments however observations during complex locomotor tasks e.g. obstacle avoidance tasks suggest that the maturation of locomotor control strategies are still developing in mid-childhood. In this area of my research program I probe how children perform cognitively demanding tasks while integrating sensory information during complex gait tasks.
At the other end of the life spectrum, my research program aims to explore how the aging process influences and changes the complex relationship between cognitive resources, sensory input and executed adaptive locomotor strategies. The increasing number of aging baby-boomers in Canada and the financial impact that falls in the elderly has on the healthcare system draws attention to the importance of this research focus.

Campbell TM, Vallis LA (2014). Predicting fat-free mass index and sarcopenia in assisted-living older adults. Age (Dordr). 36(4):9674. [Ontario Neurotrauma Foundation]

Worden TA, Vallis LA (2014). Concurrent performance of a cognitive and dynamic obstacle avoidance task: influence of dual-task training. J Mot Behav. 46(5):357-68. [NSERC Discovery Grant awarded to LAV)

Smale KB, McIntosh EI, Vallis LA (2013). Comparison of Bioelectrical Impedance Analysis and Air Displacement Plethysmography in Community-Dwelling Older Adults. J Appl Gerentol. [Epub ahead of print]. [Ontario Neurotrauma Foundation; U of G Faculty Research Assistance Award; OGS awarded to EIM]

McIntosh EI, Smale KB, Vallis LA (2013). Predicting Fat-Free Mass Index and Sarcopenia in Healthy Community Dwelling Older Adults. Age (Dordr). 35(6):2423-34. [Ontario Neurotrauma Foundation; U of G Faculty Research Assistance Award; OGS awarded to EIM]

Hackney A, Vallis LA, Cinelli ME (2013). Action strategies of individuals during aperture crossing in non-confined space. Q J Exp Psychol (Hove). 66(6): 1104-12.

Krause KE, McIntosh EI, Vallis LA (2011). Sarcopenia and predictors of the fat free mass index in community-dwelling and assisted-living older men and women. Gait Posture. 35(2): 180-5. [Ontario Neurotrauma Foundation]

Paquette MR, Vallis LA (2010). Age related kinematic changes in late visual-cueing during obstacle circumvention. Exp Brain Res 203(3): 563-74. [U of G Faculty Research Assistance Award]

Reed-Jones RJ, Vallis LA. (2009a) Modulation of visually evoked movement responses in moving virtual environments. Perception. 38(5): 652-663. 

Reed-Jones RJ, Reed-Jones JG, Vallis LA, Hollands MA. (2009b) The effects of constraining eye movements on visually evoked steering responses during walking in a virtual environment. Exp Brain Res. 197 (4): 357-67. [NSERC PGS-D awarded to RJR-J; Can Soc Biomech Graduate Student Travel Award]

Reed-Jones RJ, Hollands MA, Reed-Jones JG, Vallis LA. (2009c) Visually evoked whole body turning responses during stepping in place in a virtual environment. Gait Posture. 30(3): 317-21. [NSERC PGS-D awarded to RJR-J; Can Soc Biomech Graduate Student Travel Award]

Paquette MR, Fuller JR, Adkin AL, Vallis LA. (2008) Age-related modifications in steering behaviour: The effects of base-of-support constraints at the turn point. Exp Brain Res 190 (1): 1-9. [RBJ Schlegal-UW Center for Research in Aging]

Reed-Jones RJ, Vallis LA, Reed-Jones JG, Trick LM. (2008) The relationship between postural stability and virtual environment adaptation. Neurosci Lett. 435(3): 204-9. [OGS awarded to RJR-J]

Reed-Jones RJ, Vallis LA. (2008) Kinematics and muscular responses to a ramp descent in the ACL deficient knee. The Knee 15(2): 117-24.

Reed-Jones RJ and Vallis LA. (2007) Proprioceptive deficits of the lower limb following anterior cruciate ligament deficiency affect whole body steering control. Exp Brain Res 182 (2): 249-60

Lowrey CR, Watson A, Vallis LA. (2007) Age-related changes in avoidance strategies when negotiating single and multiple obstacles. Exp Brain Res 182 (3): 289-99. [OGS awarded to CRL; RBJ Schlegal-UW Center for Research in Aging]

Lowrey CR, Reed RJ, Vallis LA. (2007) Control strategies used by older adults during obstacle avoidance: Age-related changes. Gait Posture 25(4): 502-8. [RBJ Schlegal-UW Center for Research in Aging]

Fuller JR, Adkin AL, Vallis LA. (2007) Strategies used by older adults to change travel direction. Gait Posture 25(3): 393-400. [RBJ Schlegal-UW Center for Research in Aging]

Trick, LM, Guindon J, Vallis LA. (2006) Sequential tapping interferes selectively with multiple object tracking: Do finger-tapping and tracking share a common resource? Q J Exp Psychol (Colchester) 59(7):1188-95.

Berard J, Vallis LA. (2006) Characteristics of single and double obstacle avoidance strategies: A comparison between adults and children. Exp Brain Res 175(1):21-31.

Reed RJ, Lowrey CR, Vallis LA. (2006) Middle-old and old-old retirement dwelling adults respond differently to locomotor challenges in cluttered environments. Gait Posture 23(4): 486-9. [RBJ Schlegal-UW Center for Research in Aging]


  • HK*2270 Principles of Human Biomechanics 
  • HK*4070 Clinical Biomechanics 
  • HHNS*6200 Research Methods in Biomechanics


Breau, R. PhD Student
Coyle-Asbil, H. MSc Student
Pitman, J. PhD Student
Shulman, D. PhD Student