Gait termination in young and older adults: effects of stopping stimulus probability and stimulus delay.
Sixteen young (25 +/- 2.6 years) and 16 older individuals (69 +/- 4.4 years) walked normally then terminated walking rapidly. A visual stopping stimulus was presented 10 ms following ground contact (short delay) and in another condition, at 450 ms prior to toe-off (long delay). Stimulus probability was either high (80% of trials) or low (10%). The younger group stopped faster (463 vs. 574 ms) despite also walking faster (1.29 vs. 1.17 m s(-1)). Longer delay decreased one-step responses but older participants used significantly more (slower) two-step stopping, which increased stopping time and distance. The additional step may have been pre-planned to maintain medial-lateral stability.
Tirosh
Oren
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School of Health Sciences, Deakin University, 221 Burwood Hwy., Burwood 3125, Melbourne, Australia.
Sparrow
W A
WA
D000058:Accidental Falls / Q000517:prevention & control*; D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D003463:Cues; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology*; D011930:Reaction Time