{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T14:46:21Z","timestamp":1792593981696,"version":"4.5.0"},"reference-count":45,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2023,7,16]],"date-time":"2023-07-16T00:00:00Z","timestamp":1689465600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Substantial advancements in markerless motion capture accuracy exist, but discrepancies persist when measuring joint angles compared to those taken with a goniometer. This study integrates machine learning techniques with markerless motion capture, with an aim to enhance this accuracy. Two artificial intelligence-based libraries\u2014MediaPipe and LightGBM\u2014were employed in executing markerless motion capture and shoulder abduction angle estimation. The motion of ten healthy volunteers was captured using smartphone cameras with right shoulder abduction angles ranging from 10\u00b0 to 160\u00b0. The cameras were set diagonally at 45\u00b0, 30\u00b0, 15\u00b0, 0\u00b0, \u221215\u00b0, or \u221230\u00b0 relative to the participant situated at a distance of 3 m. To estimate the abduction angle, machine learning models were developed considering the angle data from the goniometer as the ground truth. The model performance was evaluated using the coefficient of determination R2 and mean absolute percentage error, which were 0.988 and 1.539%, respectively, for the trained model. This approach could estimate the shoulder abduction angle, even if the camera was positioned diagonally with respect to the object. Thus, the proposed models can be utilized for the real-time estimation of shoulder motion during rehabilitation or sports motion.<\/jats:p>","DOI":"10.3390\/s23146445","type":"journal-article","created":{"date-parts":[[2023,7,17]],"date-time":"2023-07-17T01:06:36Z","timestamp":1689555996000},"page":"6445","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":32,"title":["Measurement of Shoulder Abduction Angle with Posture Estimation Artificial Intelligence Model"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6046-7521","authenticated-orcid":false,"given":"Masaya","family":"Kusunose","sequence":"first","affiliation":[{"name":"Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0806-6579","authenticated-orcid":false,"given":"Atsuyuki","family":"Inui","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hanako","family":"Nishimoto","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yutaka","family":"Mifune","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tomoya","family":"Yoshikawa","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Issei","family":"Shinohara","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1681-6974","authenticated-orcid":false,"given":"Takahiro","family":"Furukawa","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tatsuo","family":"Kato","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6349-5993","authenticated-orcid":false,"given":"Shuya","family":"Tanaka","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ryosuke","family":"Kuroda","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,7,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"354","DOI":"10.1136\/bmj.316.7128.354","article-title":"Systematic review of randomized controlled trials of interventions for painful shoulder: Selection criteria, outcome assessment, and efficacy","volume":"316","author":"Green","year":"1998","journal-title":"BMJ"},{"key":"ref_2","first-page":"98","article-title":"Evaluating change in clinical status: Reliability and measures of agreement for the assessment of glenohumeral range of motion","volume":"5","author":"Muir","year":"2010","journal-title":"N. 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