Understanding the Cognitive Load of Cell Phone Use While Walking: Distinct Effects of Texting and Phone Conversation.

Background: Aging is marked by a series of changes that impair mobility. These changes are accompanied by declines in balance, postural control, and cognitive function. While the relationship between balance, postural control, and mobility has been extensively investigated, evidence on how different cognitive demands influence mobility performance in daily life remains limited. Accordingly, this study investigated how different cognitive demands associated with cell phone use affect mobility performance in young and older adults. Methods: In this cross-sectional study, 124 cognitively preserved participants (n = 62 young and n = 62 older adults) were enrolled. The participants were subjected to three walking conditions: without distraction, while texting, and while talking on the phone. Wearable motion sensors were used to quantify mobility performance across different task-specific components. Age and cognitive function were assessed to investigate their roles in mobility performance. Results: Older adults exhibited poorer gait performance than young adults, demonstrating longer completion times across multiple functional mobility tasks. Texting and phone conversations adversely affected gait performance to a similar extent. Age explained up to 42.4% of the variability in mobility performance during dual task, whereas cognitive function accounted for an additional 16.6% of the variance. Conclusions: In a cognitively preserved sample, the negative impact of cell phone use while walking was greater in older than in young adults. Age was the primary determinant of mobility performance while cognition played a lesser role. These findings support the need for interventions addressing age-related changes and cognitive demands to improve mobility in older adults.