Gait characteristics in older adults using the ProtoKinetics Zeno walkway: the atherosclerosis risk in communities (ARIC) study.

BACKGROUND: Gait speed is an important indicator of functional status and health outcomes in older adults. Electronic gait mats are common in research, but stopwatches are more feasible in clinical practice. This study compared agreement between single task (ST) gait speed measured by stopwatch and gait mat and described single and dual task (DT) gait performance measured by gait mat. METHODS: A subset of Atherosclerosis Risk in Communities (ARIC) Study Visit 8 participants completed ST cognitive (serial subtractions), ST gait speed, and DT gait (gait with serial subtractions) on an electronic gait mat; ST gait speed was also assessed by stopwatch. Bland Altman analyses examined agreement between ST gait speed methods. Adjusted linear mixed effects models estimated differences between ST and DT gait parameters. RESULTS: Among 364 participants (mean 81.8 years, 54.7% female), faster gait mat gait speeds were associated with a greater discrepancy from stopwatch measurements (β: -0.24 [95%CI: -0.31, -0.17]), indicating stopwatch underestimation. Participants exhibited mutual interference under DT, walking slower (mean difference in gait speed: -25.0 cm/s [95%CI: -26.8, -23.2]) with shorter (mean difference in step length: -6.2 cm [95%CI: -6.8, -5.6]) and wider steps (mean difference in stride width: 1.6 cm [95%CI: 1.3, 1.9]). CONCLUSION: Gait mat and stopwatch measurements showed acceptable agreement, supporting clinical use. However, greater disagreement at faster speeds suggests gait mats may be more appropriate for faster walking speeds. These findings support future investigations of ST and DT gait performance within ARIC and other aging cohorts, including relationships with cognitive decline, mobility limitations, and adverse health outcomes.