{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T07:11:34Z","timestamp":1777619494937,"version":"3.51.4"},"reference-count":44,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2024,7,26]],"date-time":"2024-07-26T00:00:00Z","timestamp":1721952000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Portuguese Foundation for Science and Technology (FCT)","award":["UIDP\/05913\/2020"],"award-info":[{"award-number":["UIDP\/05913\/2020"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Bioengineering"],"abstract":"<jats:p>The speedometer is widely used to evaluate swimming velocity but has some constraints. With the constant development of inertial units (IMUs), it is expected that they will become a good alternative to the speedometer. This study aimed to compare the data retrieved by an IMU and a speedometer when breaststroke is performed at maximum speed. Sixteen swimmers, nine males and seven females (20.3 \u00b1 3.3 vs. 18.7 \u00b1 1.1 years old, 65.8 \u00b1 11.2 vs. 57.7 \u00b1 9.1 kg of body mass and 1.75 \u00b1 0.07 vs. 1.61 \u00b1 0.10 m of height, respectively), performed 4 \u00d7 25 m of breaststroke sprint. They were equipped with an IMU fixed to the sacrum and with the line of an electromechanical speedometer (acquisition frequency of 50 Hz) fixed at the central point in the lumbar region. Statistical parametric mapping was used to compare the velocity curves, IBM SPSS was used for descriptive statistics and Bland\u2013Altman plots were used for agreement of measurements. The results show that the IMU and speedometer do not show similar patterns, and the velocity values measured by the IMU are lower (p &lt; 0.001). Bland\u2013Altman plots presented a larger bias in terms of coefficient of variation and intracycle velocity variation. It can be concluded that IMUs and speedometers are not substitutes for each other as methods for evaluating intracycle velocity variations.<\/jats:p>","DOI":"10.3390\/bioengineering11080757","type":"journal-article","created":{"date-parts":[[2024,7,26]],"date-time":"2024-07-26T06:17:44Z","timestamp":1721974664000},"page":"757","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Swimming Velocity Analysis Using Wearable Inertial Sensors and Speedometer: A Comparative Study"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6654-0814","authenticated-orcid":false,"given":"Leandro","family":"Vieira","sequence":"first","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport and Porto Biomechanics Laboratory (LABIOMEP), University of Porto, 4200-450 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5502-1202","authenticated-orcid":false,"given":"M\u00e1rio J.","family":"Costa","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport and Porto Biomechanics Laboratory (LABIOMEP), University of Porto, 4200-450 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4592-8091","authenticated-orcid":false,"given":"Catarina C.","family":"Santos","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport and Porto Biomechanics Laboratory (LABIOMEP), University of Porto, 4200-450 Porto, Portugal"},{"name":"Department of Sport Sciences, Higher Institute of Educational Sciences of the Douro (ISCE-Douro), 4560-547 Penafiel, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2070-2064","authenticated-orcid":false,"given":"Francisco A.","family":"Ferreira","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport and Porto Biomechanics Laboratory (LABIOMEP), University of Porto, 4200-450 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5811-0443","authenticated-orcid":false,"given":"Ricardo J.","family":"Fernandes","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport and Porto Biomechanics Laboratory (LABIOMEP), University of Porto, 4200-450 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8313-8181","authenticated-orcid":false,"given":"Susana","family":"Soares","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport and Porto Biomechanics Laboratory (LABIOMEP), University of Porto, 4200-450 Porto, Portugal"}]},{"given":"M\u00e1rcio F.","family":"Goethel","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport and Porto Biomechanics Laboratory (LABIOMEP), University of Porto, 4200-450 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4109-2939","authenticated-orcid":false,"given":"Jo\u00e3o Paulo","family":"Vilas-Boas","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport and Porto Biomechanics Laboratory (LABIOMEP), University of Porto, 4200-450 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2024,7,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"262","DOI":"10.1016\/j.jsams.2009.01.003","article-title":"Energetics and biomechanics as determining factors of swimming performance: Updating the state of the art","volume":"13","author":"Barbosa","year":"2010","journal-title":"J. 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