Abstract P238: Gait Characteristics in Older Adults Using the Protokinetics Zeno Walkway: The Atherosclerosis Risk in Communities Study

Abstract

Introduction: Slowed gait speed in older adults is associated higher vascular disease burden, greater risk of dementia, and falls. Gait mat measurement technology captures speed as well as additional gait parameters, with potential importance for better risk prediction and identification in older adults, but normative data are needed. We assessed correlations between mat-measured gait speed and gait parameters to identify potential targets for future gait research. We hypothesized that gait parameters would not correlate with overall mat-measured gait speed as strongly as overall gait speed correlates within repeat trials of mat or stopwatch-measured trials. Methods: Participants (n = 402, mean age: 81 years, 54% women, 19% Black race) from the Atherosclerosis Risk in Communities Study completed two consecutive usual pace walks on Zeno Walkway™ gait mats at visit 8. Two-hundred thirty-six participants additionally completed two 4-meter usual pace walks timed by stopwatch. We assessed validity using the difference between the faster of two trials each for mat- and stopwatch-measured gait speed using Bland-Altman plots, and Pearson’s correlations, and examined reliability with consecutive trials within measurement type. We reported mean, standard deviation, range, and correlation of 37 gait parameters with gait speed, as well as intra-person variability (coefficient of variation) and parameter asymmetry between footfalls. Results: Participants had an average gait speed of 0.92 m/sec (SD 0.19 m/sec) measured by mat and 0.99 m/sec (SD 0.21 m/sec) by stopwatch. Mat-measured gait speed was strongly correlated with stopwatch measured speed (Pearson’s Correlation 0.85). Mat-measured walks were on average 0.08 m/sec faster than paired stopwatch-measured walks (standard deviation of difference 0.11 m/sec, p<0.001), regardless of gait speed. Consecutive mat walks had higher Pearson’s and R-squared correlations (0.95 and 0.90) than consecutive stopwatch walks (0.89 and 0.83). Of 37 gait parameters tested, 9 were positively correlated (Pearson’s correlations 0.64 to 0.76) and 7 were negatively correlated (Pearson’s correlations -0.64 to -0.42) with gait speed. Parameter variability in single stance center of pressure distance and gait speed was moderately negatively correlated (Pearson’s correlation -0.50). Correlations between gait speed and gait parameter asymmetry were low (<|0.33|). Conclusions: Gait mat technology shows high reliability and high correlation with stop-watch measurement in older adults in the ARIC population. Additional gait parameters were largely not strongly correlated with gait speed, including step-to-step measures of variability and asymmetry, suggesting avenues for future research to evaluate gait differences more granularly as more sensitive indicators of health risk in older adults.