Effects of the lateral amplitude and regularity of upper body fluctuation on step time variability evaluated using return map analysis.

Kazuhiro Chidori,Yuji Yamamoto,Manabu Sakakibara

doi:10.1371/journal.pone.0180898

Kazuhiro Chidori, Yuji Yamamoto + Show 1 more

Open Access

https://doi.org/10.1371/journal.pone.0180898

Copy DOI

Journal: PloS one	Publication Date: Jul 10, 2017
Citations: 3	License type: CC BY 4.0

Affiliation: Chubu Gakuin University, Nagoya University

Abstract

The aim of this study was to evaluate the effects of the lateral amplitude and regularity of upper body fluctuation on step time variability. Return map analysis was used to clarify the relationship between step time variability and a history of falling. Eleven healthy, community-dwelling older adults and twelve younger adults participated in the study. All of the subjects walked 25 m at a comfortable speed. Trunk acceleration was measured using triaxial accelerometers attached to the third lumbar vertebrae (L3) and the seventh cervical vertebrae (C7). The normalized average magnitude of acceleration, the coefficient of determination ($R^2$) of the return map, and the step time variabilities, were calculated. Cluster analysis using the average fluctuation and the regularity of C7 fluctuation identified four walking patterns in the mediolateral (ML) direction. The participants with higher fluctuation and lower regularity showed significantly greater step time variability compared with the others. Additionally, elderly participants who had fallen in the past year had higher amplitude and a lower regularity of fluctuation during walking. In conclusion, by focusing on the time evolution of each step, it is possible to understand the cause of stride and/or step time variability that is associated with a risk of falls.

Highlights

Healthcare for elderly populations has become a common problem worldwide because healthcare costs affect the economy in every country
Inclusion criteria were the ability to independently perform all activities of daily living, the ability to walk for 30 m without a break, and the ability to walk without any aid
Previous studies have focused on temporal variability in walking in relation to the risk of falls in elderly people

Summary

Introduction

Healthcare for elderly populations has become a common problem worldwide because healthcare costs affect the economy in every country. Falls during gait are a major health issue in elderly people because they often lead to serious injuries such as hip fractures, hospitalization, and even death [1,2,3]. Within a 1-year period, falls occurred in over 30% of people older than 60 years living in the southern Tasmania [4]. Falls continue to be a major source of morbidity and mortality among the elderly [1,2].

Objectives

Methods

Results

Conclusion