Gait variability and fall risk in community-living older adults: a 1-year prospective study.

OBJECTIVE: To test the hypothesis that increased gait variability predicts falls among community-living older adults attending an outpatient clinic.

DESIGN: Prospective, cohort study.

SETTING: Three outpatient geriatric clinics.

PARTICIPANTS: Fifty-two community-living, ambulatory men and women aged > or = 70 years.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Subjects walked at a normal pace for up to 6 minutes wearing force-sensitive insoles that measured the gait rhythm on a stride-to-stride basis. Afterward, subjects reported fall status on a weekly basis for 1 year. The primary outcomes were the association between measures of the stride-to-stride fluctuations in gait rhythm and (1) subsequent falls during a 12-month follow-up period and (2) potential contributing factors.

RESULTS: Almost 40% of the subjects reported falling during the 12-month follow-up period. Stride time variability was 106 +/- 30 ms in subjects who subsequently fell (n = 20) and 49 +/- 4 ms in those who did not experience a fall (n = 32) during the 12-month follow-up period (p <.04). Logistic regression also showed that stride time variability predicted falls (p <.05). Stride time variability correlated significantly with multiple factors including strength, balance, gait speed, functional status, and even mental health, but these other measures did not discriminate future fallers from nonfallers.

CONCLUSIONS: These findings show both the feasibility of obtaining stride-to-stride measures of gait timing in the ambulatory setting and the potential use of gait variability measures in augmenting the prospective evaluation of fall risk in community-living older adults.