Zusammenfassung

Test retest reliability of gait variability is less than ideal, i.e. ICC <0.70. Low test-retest reliability or inconsistency of gait variability may be an indicator of impaired mobility, balance and overall health of the older adult. Our purpose was to examine the association of inconsistency of step time variability to mobility, balance and health in older adults. Participants included 46 community dwelling older adults who could ambulate independently (mean age=78.09 years, SD= 6.2). Gait characteristics were measured twice, one week apart, using a computerized walkway. Step time variability (STV) was the standard deviation of the step times for all steps recorded during one session. Mobility, balance and health were measured during the first session using gait speed and global questions of mobility, balance, health and vigor. Using the difference of the STV measures from sessions 1 and 2 two groups were created: 1) inconsistent (IN, n=14), STV difference from session to session > 0.013s, 2) consistent (CN, n=32) STV difference from session to session < 0.013s. Differences between groups were determined by independent t-tests and Chi-square. IN compared to CN, walked slower (0.83 vs 1.01 m/s) and was less likely to report good or better mobility (36% vs 78%) and balance (21% vs 63%), all p’s < 0.05. Overall health and vigor were similar between groups. Inconsistency in step time variability from week to week in older adults may not be due to measurement error, but may actually be an indicator of impaired mobility and balance.