{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,28]],"date-time":"2026-02-28T04:23:04Z","timestamp":1772252584636,"version":"3.50.1"},"reference-count":23,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2019,12,10]],"date-time":"2019-12-10T00:00:00Z","timestamp":1575936000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>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.<\/jats:p>","DOI":"10.3390\/e21121210","type":"journal-article","created":{"date-parts":[[2019,12,10]],"date-time":"2019-12-10T10:52:41Z","timestamp":1575975161000},"page":"1210","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["The Static Standing Postural Stability Measured by Average Entropy"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9356-7879","authenticated-orcid":false,"given":"Sung-Yang","family":"Wei","sequence":"first","affiliation":[{"name":"Department of Electrophyics, National Chiao Tung University, Hsinchu 30010, Taiwan"}]},{"given":"Chang Francis","family":"Hsu","sequence":"additional","affiliation":[{"name":"Department of Electrophyics, National Chiao Tung University, Hsinchu 30010, Taiwan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2668-6947","authenticated-orcid":false,"given":"Yun-Ju","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Industrial Engineering and Engineering Management, National Tsing-Hua University, Hsinchu 30013, Taiwan"}]},{"given":"Long","family":"Hsu","sequence":"additional","affiliation":[{"name":"Department of Electrophyics, National Chiao Tung University, Hsinchu 30010, Taiwan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8674-1963","authenticated-orcid":false,"given":"Sien","family":"Chi","sequence":"additional","affiliation":[{"name":"Department of Photonics, National Chiao Tung University, Hsinchu 30010, Taiwan"}]}],"member":"1968","published-online":{"date-parts":[[2019,12,10]]},"reference":[{"key":"ref_1","unstructured":"World Health Organization, and Ageing and Life Course Unit (2008). 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