{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,8]],"date-time":"2026-01-08T23:08:38Z","timestamp":1767913718324,"version":"3.49.0"},"reference-count":44,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2021,2,24]],"date-time":"2021-02-24T00:00:00Z","timestamp":1614124800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004663","name":"Ministry of Science and Technology, Taiwan","doi-asserted-by":"publisher","award":["MOST 108-2221-E-241-008"],"award-info":[{"award-number":["MOST 108-2221-E-241-008"]}],"id":[{"id":"10.13039\/501100004663","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Walking performance is usually assessed by linear analysis of walking outcome measures. However, human movements consist of both linear and nonlinear complexity components. The purpose of this study was to use bidimensional multiscale entropy analysis of ultrasound images to evaluate the effects of various walking intensities on plantar soft tissues. Twelve participants were recruited to perform six walking protocols, consisting of three speeds (slow at 1.8 mph, moderate at 3.6 mph, and fast at 5.4 mph) for two durations (10 and 20 min). A B-mode ultrasound was used to assess plantar soft tissues before and after six walking protocols. Bidimensional multiscale entropy (MSE2D) and the Complexity Index (CI) were used to quantify the changes in irregularity of the ultrasound images of the plantar soft tissues. The results showed that the CI of ultrasound images after 20 min walking increased when compared to before walking (CI4: 0.39 vs. 0.35; CI5: 0.48 vs. 0.43, p &lt; 0.05). When comparing 20 and 10 min walking protocols at 3.6 mph, the CI was higher after 20 min walking than after 10 min walking (CI4: 0.39 vs. 0.36, p &lt; 0.05; and CI5: 0.48 vs. 0.44, p &lt; 0.05). This is the first study to use bidimensional multiscale entropy analysis of ultrasound images to assess plantar soft tissues after various walking intensities.<\/jats:p>","DOI":"10.3390\/e23030264","type":"journal-article","created":{"date-parts":[[2021,2,24]],"date-time":"2021-02-24T20:53:21Z","timestamp":1614200001000},"page":"264","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Using Bidimensional Multiscale Entropy Analysis of Ultrasound Images to Assess the Effect of Various Walking Intensities on Plantar Soft Tissues"],"prefix":"10.3390","volume":"23","author":[{"given":"Ben-Yi","family":"Liau","sequence":"first","affiliation":[{"name":"Department of Biomedical Engineering, Hungkuang University, Taichung 433304, 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"}]},{"given":"Keying","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"}]},{"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 41354, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3762-7651","authenticated-orcid":false,"given":"Chunmei","family":"Cao","sequence":"additional","affiliation":[{"name":"Division of Sports Science and Physical Education, Tsinghua University, Beijing 100084, China"}],"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"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,2,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2020","DOI":"10.1001\/jama.2018.14854","article-title":"The physical activity guidelines for Americans","volume":"320","author":"Piercy","year":"2018","journal-title":"JAMA"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1146\/annurev-bioeng-070909-105223","article-title":"Biomechanics of pressure ulcer in body tissues interacting with external forces during locomotion","volume":"12","author":"Mak","year":"2010","journal-title":"Annu. 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