Declines In Running Mechanics Begin In The Third Decade Of Life

It is known that running mechanics change with age, but the majority of research has focused on comparisons of groups of “older” and “younger" runners. Without knowing when these changes occur, most studies build in an age-gap between groups. Few studies have look at age as a continuous variable to avoid the need for this gap, but these analyses assume that there is a linear between age and gait. PURPOSE: The purpose of this study was to assess changes running mechanics across an age span in a large cohort of participants. METHODS: Data from the 4HAIE study was used to assess running gait of 1315 participants ranging in age from 18-65 years. Participants ran overground at their preferred speed with kinetics and kinematics collected. Statistical analysis was completed on gait variables comparing a simple linear regression to a segmented regression while controlling for sex and activity status to determine which model better fit the data. RESULTS: Model metrics indicated that the application of the segmented regression better fit the data than simple linear regression (p < 0.05) for all variables of interest (velocity, step length, and step width). In all cases there was an age-related decline, but this decline did not begin until around the mid-30s (Figure 1). CONCLUSION: We observed an age-related decline in gait parameters, but it did not have a simple linear relationship with age. The inflection point indicating a decline began between age 30-37 depending on the variable. This is earlier than has been suspected in previous research and shows the importance of looking more closely aging and running.Figure 1: Age vs Step Length (A), Step Width (B), and Speed (C), with knot representing the inflection point in data. Blue lines represent linear regression relationship and red represents the segmented regression. This research was funded by Program 4 HAIE—Healthy Aging in Industrial Environment (grant number: CZ.02.1.01/0.0/0.0/16_019/0000798)