Aging effects on the mechanical energy transfer through the lower extremity joints during the swing phase of level walking

Hung-Bin Chen,Chih-Hsiu Cheng,Liang-Wey Chang

doi:10.1038/s41598-019-45267-z

Hung-Bin Chen, Chih-Hsiu Cheng + Show 1 more

Open Access

https://doi.org/10.1038/s41598-019-45267-z

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Abstract

Age-related changes of gait performance have been evidenced by the altered kinetic coordination of the lower extremity. However, a systematic approach to explore the gait control in terms of the mechanical energy transfer across multiple segments throughout the gait phases is still not well documented. Ten healthy elderly and ten young adults were asked to walk along a 10-meter walkway at the self-selected and fast walking speeds. The visualized energy flow model of the swing leg was established and the factor analysis was then applied to extract the high-dimensional energy flow characteristics of the swing leg. The results showed that the young adults have similar energy flow characteristics of the swing leg for both fast and self-selected walking speeds, while the elderly showed an opposite energy flow pattern especially at the fast walking speed. The hip power and the knee power were also found to mainly correspond to the swing acceleration and deceleration, respectively. This study demonstrated a valuable tool to explore the change of the gait characteristics in the elderly and could help to facilitate the understanding of the neuromuscular adaptation due to aging.

Highlights

Age-related loss of strength, balance control, and cardiorespiratory function can limit locomotion ability and result in slower walking speed, shorter step length, and deterioration of balance control[1,2]
The knee-dominated pattern represents the energy flow characteristic of swing deceleration. It could be illustrated as an upward energy transfer since there was a substantial amount of energy flowing from the foot all the way up to the pelvis and the segmental energy change rates decreased together with the knee power absorption
This study demonstrated a systematic approach to extract the energy flow characteristics of the swing leg in the young adults and elderly

Summary

Introduction

Age-related loss of strength, balance control, and cardiorespiratory function can limit locomotion ability and result in slower walking speed, shorter step length, and deterioration of balance control[1,2]. Previous studies reported that the healthy elderly showed reduced ankle plantarflexion angle/moment/power, reduced knee flexion angle, reduced knee extension moment/power, reduced hip extension angle, and increased hip flexion/extension moment/power[3,4,5,6] These evidences suggested that aging could lead to neuromuscular adaption of the lower extremity that occurs in multiple joints rather than a single one. Previous studies reported that, while making a rapid voluntary forward step for the advancement of the lower extremity, balance-impaired older adults demonstrate smaller step length, slower step reaction time, and longer step time than balance-unimpaired older adults, and these measures are closely related to fall risks[10,11,12] These findings highlight the importance to identify the age-related changes of the movement strategy during the swing phase that may predispose the elderly to slipping or tripping. Our work would help to facilitate the understanding of the neuromuscular adaptation due to aging, which can potentially contribute to the fall prevention, orthopedic treatments and rehabilitation interventions for elderly

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