{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,8]],"date-time":"2026-05-08T17:34:09Z","timestamp":1778261649610,"version":"3.51.4"},"reference-count":42,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2018,10,5]],"date-time":"2018-10-05T00:00:00Z","timestamp":1538697600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["P20 GM109090"],"award-info":[{"award-number":["P20 GM109090"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Sample entropy (SE) has relative consistency using biologically-derived, discrete data &gt;500 data points. For certain populations, collecting this quantity is not feasible and continuous data has been used. The effect of using continuous versus discrete data on SE is unknown, nor are the relative effects of sampling rate and input parameters m (comparison vector length) and r (tolerance). Eleven subjects walked for 10-minutes and continuous joint angles (480 Hz) were calculated for each lower-extremity joint. Data were downsampled (240, 120, 60 Hz) and discrete range-of-motion was calculated. SE was quantified for angles and range-of-motion at all sampling rates and multiple combinations of parameters. A differential relationship between joints was observed between range-of-motion and joint angles. Range-of-motion SE showed no difference; whereas, joint angle SE significantly decreased from ankle to knee to hip. To confirm findings from biological data, continuous signals with manipulations to frequency, amplitude, and both were generated and underwent similar analysis to the biological data. In general, changes to m, r, and sampling rate had a greater effect on continuous compared to discrete data. Discrete data was robust to sampling rate and m. It is recommended that different data types not be compared and discrete data be used for SE.<\/jats:p>","DOI":"10.3390\/e20100764","type":"journal-article","created":{"date-parts":[[2018,10,5]],"date-time":"2018-10-05T12:16:44Z","timestamp":1538741804000},"page":"764","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":52,"title":["On the Calculation of Sample Entropy Using Continuous and Discrete Human Gait Data"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2805-1339","authenticated-orcid":false,"given":"John D.","family":"McCamley","sequence":"first","affiliation":[{"name":"MORE Foundation, 18444 N 25th Ave., Suite 110, Phoenix, AZ 85023, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"William","family":"Denton","sequence":"additional","affiliation":[{"name":"Center for Research in Human Movement Variability, Department of Biomechanics, University of Nebraska at Omaha, 6160 University Drive South, Omaha, NE 68182-0860, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andrew","family":"Arnold","sequence":"additional","affiliation":[{"name":"Center for Research in Human Movement Variability, Department of Biomechanics, University of Nebraska at Omaha, 6160 University Drive South, Omaha, NE 68182-0860, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Peter C.","family":"Raffalt","sequence":"additional","affiliation":[{"name":"Julius Wolff Institute for Biomechanics and Musculoskeletal Regeneration, Charit\u00e9-Universit\u00e4tsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany"},{"name":"Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen N 2200, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6550-7759","authenticated-orcid":false,"given":"Jennifer M.","family":"Yentes","sequence":"additional","affiliation":[{"name":"Center for Research in Human Movement Variability, Department of Biomechanics, University of Nebraska at Omaha, 6160 University Drive South, Omaha, NE 68182-0860, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,10,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2297","DOI":"10.1073\/pnas.88.6.2297","article-title":"Approximate entropy as a measure of system complexity","volume":"88","author":"Pincus","year":"1991","journal-title":"Proc. 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