Baseline-dependent effect of noise-enhanced insoles on gait variability in healthy elderly walkers.
The purpose of this study was to determine whether providing subsensory stochastic-resonance mechanical vibration to the foot soles of elderly walkers could decrease gait variability. In a randomized double-blind controlled trial, 29 subjects engaged in treadmill walking while wearing sandals customized with three actuators capable of producing stochastic-resonance mechanical vibration embedded in each sole. For each subject, we determined a subsensory level of vibration stimulation. After a 5-min acclimation period of walking with the footwear, subjects were asked to walk on the treadmill for six trials, each 30s long. Trials were pair-wise random: in three trials, actuators provided subsensory vibration; in the other trials, they did not. Subjects wore reflective markers to track body motion. Stochastic-resonance mechanical stimulation exhibited baseline-dependent effects on spatial stride-to-stride variability in gait, slightly increasing variability in subjects with least baseline variability and providing greater reductions in variability for subjects with greater baseline variability (p<.001). Thus, applying stochastic-resonance mechanical vibrations on the plantar surface of the foot reduces gait variability for subjects with more variable gait. Stochastic-resonance mechanical vibrations may provide an effective intervention for preventing falls in healthy elderly walkers.
Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, United States.
Damian G
DG
Stephen
Bethany J
BJ
Wilcox
James B
JB
Niemi
Jason R
JR
Franz
Jason
J
Franz
Dr
D
Kerrigan
D Casey
DC
Kerrigan
Susan E
SE
D'Andrea
D000058:Accidental Falls / Q000517:prevention & control*; D000368:Aged; D000886:Anthropometry; D004311:Double-Blind Method; D005080:Exercise Test / Q000379:methods; D025461:Feedback, Physiological; D005260:Female; D005684:Gait / Q000502:physiology*; D015577:Geriatric Assessment / Q000379:methods; D006801:Humans; D008297:Male; D009622:Noise; D011446:Prospective Studies; D012016:Reference Values; D012775:Shoes; D013647:Task Performance and Analysis; D014732:Vibration / Q000627:therapeutic use*; D016138:Walking / Q000502:physiology