{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T03:49:51Z","timestamp":1760240991886,"version":"build-2065373602"},"reference-count":63,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2019,11,16]],"date-time":"2019-11-16T00:00:00Z","timestamp":1573862400000},"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>Participation in various physical activities requires successful postural control in response to the changes in position of our body. It is important to assess postural control for early detection of falls and foot injuries. Walking at various speeds and for various durations is essential in daily physical activities. The purpose of this study was to evaluate the changes in complexity of the center of pressure (COP) during walking at different speeds and for different durations. In this study, a total of 12 participants were recruited for walking at two speeds (slow at 3 km\/h and moderate at 6 km\/h) for two durations (10 and 20 min). An insole-type plantar pressure measurement system was used to measure and calculate COP as participants walked on a treadmill. Multiscale entropy (MSE) was used to quantify the complexity of COP. Our results showed that the complexity of COP significantly decreased (p &lt; 0.05) after 20 min of walking (complexity index, CI = \u22123.51) compared to 10 min of walking (CI = \u22123.20) while walking at 3 km\/h, but not at 6 km\/h. Our results also showed that the complexity index of COP indicated a significant difference (p &lt; 0.05) between walking at speeds of 3 km\/h (CI = \u22123.2) and 6 km\/h (CI = \u22123.6) at the walking duration of 10 min, but not at 20 min. This study demonstrated an interaction between walking speeds and walking durations on the complexity of COP.<\/jats:p>","DOI":"10.3390\/e21111128","type":"journal-article","created":{"date-parts":[[2019,11,18]],"date-time":"2019-11-18T04:31:10Z","timestamp":1574051470000},"page":"1128","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Complexity-Based Measures of Postural Sway during Walking at Different Speeds and Durations Using Multiscale Entropy"],"prefix":"10.3390","volume":"21","author":[{"given":"Ben-Yi","family":"Liau","sequence":"first","affiliation":[{"name":"Department of Biomedical Engineering, Hung Kuang University, Taichung 443, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fu-Lien","family":"Wu","sequence":"additional","affiliation":[{"name":"Rehabilitation Engineering Lab, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7048-2493","authenticated-orcid":false,"given":"Chi-Wen","family":"Lung","sequence":"additional","affiliation":[{"name":"Rehabilitation Engineering Lab, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA"},{"name":"Department of Creative Product Design, Asia University, Taichung 443, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xueyan","family":"Zhang","sequence":"additional","affiliation":[{"name":"Rehabilitation Engineering Lab, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaoling","family":"Wang","sequence":"additional","affiliation":[{"name":"Rehabilitation Engineering Lab, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7149-4034","authenticated-orcid":false,"given":"Yih-Kuen","family":"Jan","sequence":"additional","affiliation":[{"name":"Rehabilitation Engineering Lab, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA"},{"name":"Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 10000, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,11,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"7926","DOI":"10.3390\/e17127849","article-title":"Multiscale Entropy Analysis of Center-of-Pressure Dynamics in Human Postural Control: Methodological Considerations","volume":"17","author":"Gow","year":"2015","journal-title":"Entropy"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Hu, X.Y., Zhao, J., Peng, D.S., Sun, Z.L., and Qu, X.D. 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