The Contribution of Gait Parameters to the Decline in Walking Performance Across Adulthood

This cross-sectional study examined the change in walking performance across adulthood using the 6-minute walking test, the 10-meter walking test (10MWT) and the timed-up and go. Seventy-seven participants were divided into five groups [Young (Y: 20-39 years), Middle-aged (M: 40-59 years), Young-old (YO: 60-69 years), Old (O: 70-79 years), Older-old adults (OO: 80+ years)] performed the three walking tests. In addition, different gait parameters were measured during the 10MWT using Optogait system. Analysis of variances indicated that performances on the three tests were better for Y and M compared to YO, O and OO (<i>p</i> < .001). Breakpoint analysis indicated that performance across the different walking tests started to worsen around 50 years old. Multiple regression showed that step length, stance duration, and sex explained 89% of the variance in 10MWT performance. However, mediation analyses revealed that PF force influenced step length but did not mediate its effect on walking speed, while it significantly mediated the stance duration-performance relationship. Age impacted both gait parameters but only mediated the impact of stance duration on performance. Additionally, PF force mediated the age-step length relation. These findings reveal an age-related decline in walking performance, regardless of task complexity, and demonstrate that the relationship between step length and stance duration with walking speed is influenced by PF force and age. This offers a novel framework for early detection and interventions targeting stance-phase control and step length to preserve mobility and independence in the aging population.