{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,16]],"date-time":"2026-06-16T14:30:32Z","timestamp":1781620232658,"version":"3.54.5"},"reference-count":57,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2020,5,27]],"date-time":"2020-05-27T00:00:00Z","timestamp":1590537600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001588","name":"Enterprise Ireland","doi-asserted-by":"publisher","award":["CF-2015-0031-P"],"award-info":[{"award-number":["CF-2015-0031-P"]}],"id":[{"id":"10.13039\/501100001588","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001602","name":"Science Foundation Ireland","doi-asserted-by":"publisher","award":["12\/RC\/2289-P2"],"award-info":[{"award-number":["12\/RC\/2289-P2"]}],"id":[{"id":"10.13039\/501100001602","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Anterior cruciate ligament (ACL) injuries are common among athletes. Despite a successful return to sport (RTS) for most of the injured athletes, a significant proportion do not return to competitive levels, and thus RTS post ACL reconstruction still represents a challenge for clinicians. Wearable sensors, owing to their small size and low cost, can represent an opportunity for the management of athletes on-the-field after RTS by providing guidance to associated clinicians. In particular, this study aims to investigate the ability of a set of inertial sensors worn on the lower-limbs by rugby players involved in a change-of-direction (COD) activity to differentiate between healthy and post-ACL groups via the use of machine learning. Twelve male participants (six healthy and six post-ACL athletes who were deemed to have successfully returned to competitive rugby and tested in the 5\u201310 year period following the injury) were recruited for the study. Time- and frequency-domain features were extracted from the raw inertial data collected. Several machine learning models were tested, such as k-nearest neighbors, na\u00efve Bayes, support vector machine, gradient boosting tree, multi-layer perceptron, and stacking. Feature selection was implemented in the learning model, and leave-one-subject-out cross-validation (LOSO-CV) was adopted to estimate training and test errors. Results obtained show that it is possible to correctly discriminate between healthy and post-ACL injury subjects with an accuracy of 73.07% (multi-layer perceptron) and sensitivity of 81.8% (gradient boosting). The results of this study demonstrate the feasibility of using body-worn motion sensors and machine learning approaches for the identification of post-ACL gait patterns in athletes performing sport tasks on-the-field even a number of years after the injury occurred.<\/jats:p>","DOI":"10.3390\/s20113029","type":"journal-article","created":{"date-parts":[[2020,5,28]],"date-time":"2020-05-28T12:36:58Z","timestamp":1590669418000},"page":"3029","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":42,"title":["Motion Sensors-Based Machine Learning Approach for the Identification of Anterior Cruciate Ligament Gait Patterns in On-the-Field Activities in Rugby Players"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7752-2240","authenticated-orcid":false,"given":"Salvatore","family":"Tedesco","sequence":"first","affiliation":[{"name":"Tyndall National Institute, University College Cork, Lee Maltings Complex, Dyke Parade, T12R5CP Cork, Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Colum","family":"Crowe","sequence":"additional","affiliation":[{"name":"Tyndall National Institute, University College Cork, Lee Maltings Complex, Dyke Parade, T12R5CP Cork, Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrew","family":"Ryan","sequence":"additional","affiliation":[{"name":"School of Allied Health, Health Research Institute, University of Limerick, V94T9PX Limerick, Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marco","family":"Sica","sequence":"additional","affiliation":[{"name":"Tyndall National Institute, University College Cork, Lee Maltings Complex, Dyke Parade, T12R5CP Cork, Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2163-2168","authenticated-orcid":false,"given":"Sebastian","family":"Scheurer","sequence":"additional","affiliation":[{"name":"Insight Centre for Data Analytics, School of Computer Science and Information Technology, University College Cork, T12XF62 Cork, Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amanda M.","family":"Clifford","sequence":"additional","affiliation":[{"name":"School of Allied Health, Health Research Institute, University of Limerick, V94T9PX Limerick, Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1853-0723","authenticated-orcid":false,"given":"Kenneth N.","family":"Brown","sequence":"additional","affiliation":[{"name":"Insight Centre for Data Analytics, School of Computer Science and Information Technology, University College Cork, T12XF62 Cork, Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5522-2597","authenticated-orcid":false,"given":"Brendan","family":"O\u2019Flynn","sequence":"additional","affiliation":[{"name":"Tyndall National Institute, University College Cork, Lee Maltings Complex, Dyke Parade, T12R5CP Cork, Ireland"},{"name":"Insight Centre for Data Analytics, School of Computer Science and Information Technology, University College Cork, T12XF62 Cork, Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,5,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1007\/s12178-017-9426-3","article-title":"ACL rehabilitation progression: Where are we now?","volume":"10","author":"Cavanaugh","year":"2017","journal-title":"Curr. 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