The Effect of Age on Gait Speed When Texting.

Texting while walking exerts a high cognitive load, and may be a sensitive test of the integrity of the cognitive-motor interface. We aimed to investigate the association between chronological age and gait speed while texting. A convenience sample of 308 community-dwellers was recruited: n ≥ 50 in each age group (20-29, 30-39, 40-49, 50-59) and n = 100 aged ≥60 years. Gait speed was measured over 10 metres under two experimental conditions: 1) walking at usual pace; 2) walking at usual pace while texting the message "Good morning Harry" on their smartphone. Both median gait speed with and without texting decreased with increasing age ( < 0.001). The differences between single- and dual-task gait speed were substantial for each age group and increased after the age of 50 years ( < 0.001). Median gait speeds while texting in people aged 50-59 (1.07 m/s) and ≥60 years (1.00 m/s) were below the recommended minimum for safely crossing roads (1.20 m/s). Texting while walking currently exposes people aged 50 and over to considerable environmental hazards. The significant slowing of gait speed while texting from middle age may be a marker of neurodegeneration, a cohort effect, or an appropriate compensatory response to reduce the risk of injury.