The Static Standing Postural Stability Measured by Average Entropy

Sung-Yang Wei,Chang Francis Hsu,Sien Chi,Yun-Ju Lee,Long Hsu

doi:10.3390/e21121210

Sung-Yang Wei, Chang Francis Hsu + Show 3 more

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https://doi.org/10.3390/e21121210

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Abstract

Static standing postural stability has been measured by multiscale entropy (MSE), which is used to measure complexity. In this study, we used the average entropy (AE) to measure the static standing postural stability, as AE is a good measure of disorder. The center of pressure (COP) trajectories were collected from 11 subjects under four kinds of balance conditions, from stable to unstable: bipedal with open eyes, bipedal with closed eyes, unipedal with open eyes, and unipedal with closed eyes. The AE, entropy of entropy (EoE), and MSE methods were used to analyze these COP data, and EoE was found to be a good measure of complexity. The AE of the 11 subjects sequentially increased by 100% as the balance conditions progressed from stable to unstable, but the results of EoE and MSE did not follow this trend. Therefore, AE, rather than EoE or MSE, is a good measure of static standing postural stability. Furthermore, the comparison of EoE and AE plots exhibited an inverted U curve, which is another example of a complexity versus disorder inverted U curve.

Highlights

Postural stability is a major public health concern in modern society
Any disturbance from the surroundings or subjects’ breathing could cause an increase in static standing postural instability [3], and such a loss of static standing postural stability can be shown in the center of pressure (COP) or the center of foot pressure (CFP) trajectory [4,5,6]
2017, we proposed to measure the complexity with congestive heart failure (CHF), and patients with atrial fibrillation (AF)

Summary

Introduction

Postural stability is a major public health concern in modern society. Based on a World HealthOrganization (WHO) global report [1], approximately 28%–35% of people aged of 65 years and over fall each year, and this rate increases to 32%–42% for those over 70 years of age. Postural stability is a major public health concern in modern society. The average cost of hospitalization for instability-related injuries for people 65 years and older in the United States is projected to increase to US $240 billion by 2040. Accurate identification of individual postural instability factors, including impaired balance and poor vision, can greatly increase the likelihood of selecting an appropriate prevention or treatment strategy that is targeted to meet the needs of the individual person [1]. Any disturbance from the surroundings or subjects’ breathing could cause an increase in static standing postural instability [3], and such a loss of static standing postural stability can be shown in the center of pressure (COP) or the center of foot pressure (CFP) trajectory [4,5,6].

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