{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T21:35:12Z","timestamp":1785447312373,"version":"3.56.0"},"reference-count":50,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2017,2,16]],"date-time":"2017-02-16T00:00:00Z","timestamp":1487203200000},"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>Aging causes foot arches to collapse, possibly leading to foot deformities and falls. This paper proposes a set of measures involving an entropy-based method used for two groups of young adults with dissimilar foot arches to explore and quantize postural stability on a force plate in an upright position. Fifty-four healthy young adults aged 18\u201330 years participated in this study. These were categorized into two groups: normal (37 participants) and flatfooted (17 participants). We collected the center of pressure (COP) displacement trajectories of participants during upright standing, on a force plate, in a static position, with eyes open (EO), or eyes closed (EC). These nonstationary time-series signals were quantized using entropy-based measures and traditional measures used to assess postural stability, and the results obtained from these measures were compared. The appropriate combinations of entropy-based measures revealed that, with respect to postural stability, the two groups differed significantly (p &lt; 0.05) under both EO and EC conditions. The traditional commonly-used COP-based measures only revealed differences under EO conditions. Entropy-based measures are thus suitable for examining differences in postural stability for flatfooted people, and may be used by clinicians after further refinement.<\/jats:p>","DOI":"10.3390\/e19020076","type":"journal-article","created":{"date-parts":[[2017,2,16]],"date-time":"2017-02-16T12:55:34Z","timestamp":1487249734000},"page":"76","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["A Comparison of Postural Stability during Upright Standing between Normal and Flatfooted Individuals, Based on COP-Based Measures"],"prefix":"10.3390","volume":"19","author":[{"given":"Tsui-Chiao","family":"Chao","sequence":"first","affiliation":[{"name":"Department of Industrial Engineering and Management, Yuan Ze University, Taoyuan, Chung-Li 32003, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bernard","family":"Jiang","sequence":"additional","affiliation":[{"name":"Department of Industrial Management, National Taiwan University of Science and Technology, Taipei 10607, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2017,2,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/j.gaitpost.2006.07.009","article-title":"Age-related differences in foot structure and function","volume":"26","author":"Scott","year":"2007","journal-title":"Gait Posture"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"426","DOI":"10.2106\/00004623-198769030-00014","article-title":"The longitudinal arch: A survey of eight hundred and eighty-two feet in normal children and adults","volume":"69","author":"Staheli","year":"1987","journal-title":"J. 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