Presentation Title

The Effect of Vibrotactile Stimulation on Long Range Correltion of Stride Interval Time Series Among Different Walking Speeds

Advisor Information

Ka-Chun Siu

Location

Milo Bail Student Center Ballroom

Presentation Type

Poster

Start Date

8-3-2013 9:00 AM

End Date

8-3-2013 12:00 PM

Abstract

The variability of stride interval (duration between two consecutive heel-contacts of the same leg) is one of indicators to control posture and predict falls during walking. Vibrotactile stimulation (VS) on the plantar foot shows the benefits to reduce postural sway in standing as well as decrease stride interval variability during walking. In addition, stride interval variability is also affected by different speeds. Therefore, the purpose of this study was to investigate the effect of VS and different speeds on changes of stride interval variability. We recruited ten healthy young adults to walk on treadmill with or without VS at five different speeds (preferred walking speed, PWS; 80%, 90%, 110% and 120% PWS). The VS was given by three actuators embedded in the insole with 250Hz and gain of 17.5 db. Gait characteristics were collected by motion capture system. Detrended Fluctuation Analysis was performed on the stride interval time series to determine the strength of long-range correlations over time and provide a measure of the temporal structure of variability (α-value). A two-way ANOVA (conditions; speeds) with repeated measure was used to investigate the effect of VS and speed on the stride interval time series. Post hoc analysis was performed using the Tukey test when a significant main effect was found. We found the smaller α-values at PWS indicating gait variability at PWS exhibits more effective adaptability than those at faster or slower speeds; VS also enhanced this characteristic and made the system more adaptable to environmental stresses.

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Mar 8th, 9:00 AM Mar 8th, 12:00 PM

The Effect of Vibrotactile Stimulation on Long Range Correltion of Stride Interval Time Series Among Different Walking Speeds

Milo Bail Student Center Ballroom

The variability of stride interval (duration between two consecutive heel-contacts of the same leg) is one of indicators to control posture and predict falls during walking. Vibrotactile stimulation (VS) on the plantar foot shows the benefits to reduce postural sway in standing as well as decrease stride interval variability during walking. In addition, stride interval variability is also affected by different speeds. Therefore, the purpose of this study was to investigate the effect of VS and different speeds on changes of stride interval variability. We recruited ten healthy young adults to walk on treadmill with or without VS at five different speeds (preferred walking speed, PWS; 80%, 90%, 110% and 120% PWS). The VS was given by three actuators embedded in the insole with 250Hz and gain of 17.5 db. Gait characteristics were collected by motion capture system. Detrended Fluctuation Analysis was performed on the stride interval time series to determine the strength of long-range correlations over time and provide a measure of the temporal structure of variability (α-value). A two-way ANOVA (conditions; speeds) with repeated measure was used to investigate the effect of VS and speed on the stride interval time series. Post hoc analysis was performed using the Tukey test when a significant main effect was found. We found the smaller α-values at PWS indicating gait variability at PWS exhibits more effective adaptability than those at faster or slower speeds; VS also enhanced this characteristic and made the system more adaptable to environmental stresses.