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stride length
- from foot strike to foot strike of same foot
- aka gait cycle
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R/L step lengths?
stepping forward with that foot, distance from back heel to the front heel
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break up into %s of time spent in swing, stance, and elements of stance
- swing: 40%
- stance: 60%
- initial double stance - 10%
- single limb support - 40%
- terminal double stance - 10%
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which is the most demanding task in the gait cycle? why?
- initial contact and loading
- bc 3 functional patterns ar needed -- shock absorption, initial limb stability, perservation of progress
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key muscles in initial contact and loading phase
hip extensors, quads, DFers
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kinematics
displacement/movement w/o respect to force
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kinetics
force, distance, velocity
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kinematic changes at the ankle in elderly
- decreased PF to DF ROM
- decreased peak PF
- greater toe out angle
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kinetic changes in ankle in the elderly
- lower PF moment and poer
- peak PF force occurs earlier in ROM
- (so increase PF force to help gait)
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changes in knee kinematics in elderly
- decreased ROM (55° vs 59°)
- extension angle at midstance decreased .5°/decade
- swing phase angle decreases .5-.8°/decade
- slight kne flexion at end of swing (this decreases quad demand for loading and correlates w shorter stride length)
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knee kinetics in elderly
- higher energy absorption btwn stance and swing
- lower peak knee absorption power
- knee OA decreases knee power
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hip keniematics
- ROM increases (40° vs 32°)
- they accomodate for the increased extension w APT bc they have flexion contractures
- shorter step lenght
- lower hip AP accelerations (1.54m/s vs 1.91 m/s)
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hip kinetics
compensations at hip produce higher concentric hip power, greater pull-off (sternght leaving ground)
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diminished hip ext -->?
decreased push-off in late stance
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change in head A/P accelleration w age?
increase - .62 m/s2 vs .48 m/s2
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head mvmnt attenuation old vs yng
58% vs 72%
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limb speed acceleration in elderly vs youth
higher A/P and M/L accelerations
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