20 Smartphone usage during walking decreases the positive persistency in gait cycle variability

Oregon Convention Center 

Gait cycle variability during steady walking, characterized by the stride interval time series, has been
used as a measure of gait stability. Positive persistency (long-range positive
correlation), representing a 1/f-like fluctuation of stride interval, in healthy young adults and
reduction of persistency due to aging and/or neurological diseases, respectively, are well-
documented metrics for stability and instability of gait. We examined effects of a dual task on
gait cycle variability in healthy young adults, based on the mean and std dev statistics as
well as the positive persistency of the treadmill stride interval time series during walking .
Three gait conditions were examined: control condition, non-cognitive task holding
a smartphone in front of chest using dominant hand and looking fixedly at a blank screen of
smartphone, and cognitive task with holding smartphone as in non-cognitive task and
playing a puzzle game displayed on the smartphone by one-thumb operation. Only
positive persistency was affected by the cognitive and motor load of smartphone usage.Positive persistency in the
control & non-cognitive conditions was significantly reduced in cogniive case

repeated measures MANOVA

long-range correlation

stride interval,

gait
stability, cognitive task, motor task, dual-tasking. 

Section on Medical Devices and Diagnostics