Dr. Lori Ann Vallis
Associate Professor

Dr. Lori A. Vallis

Email: lvallis@uoguelph.ca

Office: ANNU 343
Ext: 54589
Lab: ANNU 208
Ext: 54166


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. - Ottawa University
M.Sc. - Ottawa University
Ph.D. - University of Waterloo


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 stationary and dynamic obstacles in the travel path, delivery of a head perturbation, delivery of galvanic vestibular stimulation, exposure to altered sensory information in virtual reality environments.


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

Referred journal publications: Published

Graduate and undergraduate students under Dr. Vallis' supervision:
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. [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. [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.

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. [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]

(+ 4 articles between 2001 and 2005)

Papers submitted to referred journals
McIntosh EI, Smale KB, Vallis LA (2011). Predicting Fat-Free Mass Index and Sarcopenia in Healthy Community Dwelling Older Adults. Submitted, July 2012. AGE: J American Aging Association [Ontario Neurotrauma Foundation].

Smale KB, McIntosh EI, Vallis LA (2011). Comparison of Bioelectrical Impedance Analysis and Air Displacement Plethysmography in Community-Dwelling Older Adults. Submitted May 4, 2012 J Appl Gerontol (JAG-12-0110) [Ontario Neurotrauma Foundation].

Hackney A, Vallis LA, Cinelli ME. Action strategies of individuals during aperture crossing in non-confined space Submitted, Q J Exp Psychol (Colchester); May 29, 2012 [QJE-STD 12-179].


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

Grad Students

E. McIntosh (MSc student)
T. Worden (MSc student)
T. Campbell (MSc student)



University of Guelph
50 Stone Road East
Guelph, Ontario, N1G 2W1

Human Health &
Nutritional Sciences

Animal Science/
Nutrition Building
519-824-4120 x56171
Fax: 519-763-5902