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Biomechanics of Gait Initiation and Termination. D. Gordon E. Robertson, PhD, FCSB Richard Smith. PhD, U. Sydney Nader Farapour, PhD, U. Tehran Natasha Kyle Joe Lynch Biomechanics, Laboratory, School of Human Kinetics, University of Ottawa, Ottawa, Canada. Initiation of Gait: Events.
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Biomechanics of Gait Initiation and Termination D. Gordon E. Robertson, PhD, FCSB Richard Smith. PhD, U. Sydney Nader Farapour, PhD, U. Tehran Natasha Kyle Joe Lynch Biomechanics, Laboratory, School of Human Kinetics, University of Ottawa, Ottawa, Canada
Initiation of Gait:Events Quiet stance First toe-off (lead-leg) Second toe-off (trail-leg)
trail line of gravity step 2 both Notice that as the combined centre of pressure moves backwards and towards the lead-leg the line of gravity proceeds forwards and towards the trail-leg. The line of gravity is outside the base of support shortly after the lead-leg lifts. lead step 1 Results:Centres of Pressure
Biomechanics of Ramp Ascent and Descent D. Gordon E. Robertson, PhD, FCSB Robyn Wharf Andrew Post Biomechanics, Laboratory, School of Human Kinetics, University of Ottawa, Ottawa, Canada
Ramp Ascent Study(Robyn Wharf) • level, 3-, 6- and 9-degree inclines • one step before ramp • opposite leg on ramp • 2nd step on ramp Force platforms
Moments Powers hip Ramp Ascent • very few differences in the moments of force • powers were more diagnostic • level walking and 3-degrees almost same • 6- and 9-degree inclines were sig. different knee ankle
Biomechanics of Stair Ascent and Descent D. Gordon E. Robertson, PhD, FCSB Tyler Cluff François D. Beaulieu Andrew Post Stefan Potozny Biomechanics, Laboratory, School of Human Kinetics, University of Ottawa, Ottawa, Canada
Motion Analysis Tools Reflective markers Infrared cameras and EMGs Force platforms
Laboratory Stairs • Step height = 20 cm • Step tread = 30 cm • Railings = 91 cm • Height and tread are adjustable Force platforms
Backwards Stair Descent Down Two Stairs Backwards to Landing
Centre of pressure and centre of gravity are farther from edge of stairs If tripping occurs person falls into stairs not down stairs Person will be more inclined to use handrails Moments and powers were smaller than forwards but larger than walking No concentric ankle power needed (e.g., B-K amputees) Discussion Benefits of Backwards Stair Descent
Discussion Concerns with Backwards Stair Descent • Problems with seeing next step and landing • Unconventional therefore may affect compliance • Does require railings for most people • Irregular stairs may be problematic
Not the most dignified stair descent (5 point!) Il Castillo, Chichen Itza, Mexico
grand jette jumping mechanics simulation Ballet Biomechanics • pirouette • fouette