1. Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
2. Structure and Motion Laboratory, Department of Veterinary Basic Sciences, The Royal Veterinary College, London NW1 0TU, UK
3. Faculty of Physical Education and Recreation, Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada T6G 2H9
4. Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA
5. Department of Medicine and Family Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H9