{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,2]],"date-time":"2026-06-02T23:16:57Z","timestamp":1780442217569,"version":"3.54.1"},"reference-count":29,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2021,1,6]],"date-time":"2021-01-06T00:00:00Z","timestamp":1609891200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100005969","name":"Universit\u00e0 di Bologna","doi-asserted-by":"publisher","award":["ALMA IDEA Junior 2017"],"award-info":[{"award-number":["ALMA IDEA Junior 2017"]}],"id":[{"id":"10.13039\/501100005969","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The present study aimed to explore the variability of the arm-stroke temporal descriptors between and within laps during middle-distance swimming event using IMMUs. Eight male swimmers performed a 200-m maximum front-crawl in which the inter-lap and intra-lap variability of velocity, stroke rate, stroke-phases duration and arm-coordination index were measured through five units of IMMU. An algorithm computes the 3D coordinates of the wrist by means the IMMU orientation and the kinematic chain of upper arm biomechanical model, and it recognizes the start events of the four arm-stroke phases. Velocity and stroke rate had a mean value of 1.47 \u00b1 0.10 m\u00b7s\u22121 and 32.94 \u00b1 4.84 cycles\u00b7min\u22121, respectively, and a significant decrease along the 200-m (p &lt; 0.001; \u03b72 = 0.80 and 0.47). The end of each lap showed significantly lower stroke rate compared to the start and the middle segment (p &lt; 0.05; \u03b72 = 0.55). No other significant inter-lap and intra-lap differences were detected. The two main findings are: (i) IMMUs technology can be an effective solution to continuously monitor the temporal descriptors during the swimming trial; (ii) swimmers are able to keep stable their temporal technique descriptors in a middle-distance event, despite the decrease of velocity and stroke rate.<\/jats:p>","DOI":"10.3390\/s21020324","type":"journal-article","created":{"date-parts":[[2021,1,6]],"date-time":"2021-01-06T20:45:42Z","timestamp":1609965942000},"page":"324","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Arm-Stroke Descriptor Variability during 200-m Front Crawl Swimming"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1518-8221","authenticated-orcid":false,"given":"Matteo","family":"Cortesi","sequence":"first","affiliation":[{"name":"Department for Life Quality Studies, University of Bologna, 47921 Rimini, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rocco","family":"Di Michele","sequence":"additional","affiliation":[{"name":"Department of Biomedical and Neuromotor Sciences, University of Bologna, 40127 Bologna, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0660-7204","authenticated-orcid":false,"given":"Silvia","family":"Fantozzi","sequence":"additional","affiliation":[{"name":"Department of Electrical, Electronic and Information Engineering, University of Bologna, 40136 Bologna, Italy"},{"name":"Health Sciences and Technologies\u2014Interdepartmental Center for Industrial Research, University of Bologna, Via Tolara di Sopra, 50, 40064 Ozzano dell\u2019Emilia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0053-397X","authenticated-orcid":false,"given":"Sandro","family":"Bartolomei","sequence":"additional","affiliation":[{"name":"Department of Biomedical and Neuromotor Sciences, University of Bologna, 40127 Bologna, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6322-7761","authenticated-orcid":false,"given":"Giorgio","family":"Gatta","sequence":"additional","affiliation":[{"name":"Department for Life Quality Studies, University of Bologna, 47921 Rimini, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,6]]},"reference":[{"key":"ref_1","first-page":"438","article-title":"Inertial Sensors in Swimming: Detection of Stroke Phases through 3D Wrist Trajectory","volume":"18","author":"Cortesi","year":"2019","journal-title":"J. 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