Mental Fatigue Increases Gait Variability During Dual-task Walking in Old Adults

Area of Science:

• Gerontology
• Cognitive Neuroscience
• Biomechanics

Background:

• Mental fatigue, a state from sustained cognitive effort, is common.
• Its impact on older adults' gait is under investigation.
• This study examines mental fatigue's effect on gait in young and old individuals.

Purpose of the Study:

• To investigate the impact of mental fatigue on gait performance.
• To compare effects in young versus old adults under single- and dual-task conditions.
• To assess changes in subjective and psychophysiological states.

Main Methods:

• 16 young and 16 old adults underwent a 90-minute mental fatigue or control task.
• Spatio-temporal gait parameters were measured using a photoelectric system.
• Subjective fatigue, mood, arousal, and heart rate variability were assessed.

Main Results:

• Mental fatigue increased subjective tiredness and arousal, and decreased mood and wakefulness.
• Older adults showed higher psychophysiological workload during mental fatigue.
• Gait performance, specifically dual-task walking, was impaired in older adults post-mental fatigue.

Conclusions:

• Mental fatigue impairs dual-task gait in older adults.
• This susceptibility may represent a novel intrinsic fall risk factor.
• Consider mental fatigue in dual-task gait analyses for older populations.