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

Area of Science:

• Biomechanics
• Neuroscience
• Human Movement Science

Background:

• Gait cycle variability, specifically stride interval time series, serves as a measure of gait stability.
• Positive persistency in stride intervals with 1/f-like fluctuations characterizes healthy gait, while its reduction is observed in elderly and neurological patients.

Purpose of the Study:

• To investigate the impact of dual-tasking, specifically smartphone usage, on gait cycle variability in healthy young adults.
• To differentiate the effects of cognitive load versus non-cognitive smartphone tasks on gait stability metrics.

Main Methods:

• Participants walked on a treadmill under three conditions: control, non-cognitive smartphone task (holding and viewing), and cognitive-motor task (playing a game).
• Gait cycle variability was assessed using mean and standard deviation of stride intervals, and importantly, the positive persistency of stride intervals.
• Statistical analysis was performed to compare gait parameters across the three conditions.

Main Results:

• The mean and standard deviation of stride intervals were not significantly affected by smartphone usage.
• Positive persistency of stride intervals significantly decreased during the cognitive-motor task compared to control and non-cognitive conditions.
• This reduction in positive persistency suggests a deterioration of gait pattern under cognitive and motor load.

Conclusions:

• Cognitive and motor load associated with smartphone use, specifically playing a game, negatively impacts gait stability in healthy young adults.
• The observed decrease in positive persistency is likely an endogenous effect of cognitive and motor demands, rather than a consequence of reduced visual field.
• These findings highlight the sensitivity of gait stability to dual-tasking and suggest potential implications for fall risk in complex environments.