Association of walk ratio during normal gait speed and fall in community-dwelling elderly people.

BACKGROUND

Walk ratio (WR), calculated by dividing step length by cadence, can be used to represent the gait characteristics of human beings to maintain their gait speed.

RESEARCH QUESTION

The aim of this study was to examine whether WR could distinguish fallers from community-dwelling elderly people.

METHODS

We recruited 9205 elderly people (mean age: 73.7 ± 5.6 years, 4218 men and 4987 women) from the National Center for Geriatrics and Gerontology - Study of Geriatric Syndromes. Fall history was assessed by face-to-face interview, and "fallers" were defined as people who had fallen at least once within the past year. WR was calculated as corrected step length divided by corrected cadence, and we divided the subjects into three groups according to the tertile of WR (T1, T2, and T3). We also stratified the participants by gait speed (<1.0 or ≥1.0 m/s).

RESULTS

With reference to the T3 group, the T1 group had a higher odds ratio (OR) of falling in the past year [OR: 1.24, 95% confidence interval (CI): 1.09-1.41], even after adjusting for other covariates. After stratification by gait speed, the same multivariate analyses were conducted. In the participants who walked at 1.0 m/s or faster, the T1 group had a higher OR [1.27, 95% confidence interval (CI): 1.10-1.48], while there was no significant association with fall rate among those who walked slower than 1.0 m/s.

SIGNIFICANCE

This study revealed that the smallest WR was independently associated with falling in the past year among community-dwelling elderly people, especially elderly people with no deterioration of gait speed. These results suggest that intervention regarding gait pattern, especially WR, would help to prevent falls.