{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T13:02:27Z","timestamp":1789650147630,"version":"4.0.0"},"reference-count":51,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T00:00:00Z","timestamp":1789603200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Clin. Med.","JCM"],"abstract":"<jats:p>Return-to-play (RTP) decisions after severe knee injury in elite athletes remain challenging because functional recovery may not coincide with physiological tissue recovery. This longitudinal case report evaluated Advanced 19-Frequency Bioelectrical Impedance Vector Analysis (A19FBIVA) as a non-invasive sensor-based approach for monitoring segmental lower-limb bioelectrical changes in an elite female alpine skier following a complex right knee injury. Segmental resistance (R), reactance (Xc), phase angle (PhA), and inter-limb asymmetry were assessed with a Seca mBCA 515 analyzer at 19 frequencies (1\u20131000 kHz) at four time points: 5 days pre-injury, 26 days post-injury, 64 days post-injury, and 135 days post-injury. The rare pre-injury baseline enabled individualized comparison beyond contralateral symmetry. At the final late-stage rehabilitation follow-up, R in the injured lower-limb segment had normalized or improved, whereas Xc and PhA remained suppressed, indicating an observational bioelectrical pattern consistent with persistent capacitance-related impairment rather than direct evidence of localized knee-tissue healing. The uninjured limb also deteriorated during early rehabilitation, demonstrating that contralateral comparison alone may underestimate residual deficits. These findings support the exploratory concept of a \u2018reactance lag\u2019 and indicate that A19FBIVA may provide a useful complementary monitoring layer, alongside clinical examination, imaging, functional testing, and sport-specific assessment. Larger prospective studies are required to validate thresholds, reliability, and prognostic value.<\/jats:p>","DOI":"10.3390\/jcm15187231","type":"journal-article","created":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T11:41:35Z","timestamp":1789645295000},"page":"7231","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Bioelectrical Recovery After Knee Injury in an Elite Alpine Skier: A Longitudinal 19-Frequency Bioelectrical Impedance Vector Analysis Case Report"],"prefix":"10.3390","volume":"15","author":[{"given":"Stanislav","family":"\u0160tuhec","sequence":"first","affiliation":[{"name":"Faculty of Sport, University of Ljubljana, Gortanova 22, 1000 Ljubljana, Slovenia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tina","family":"Robnik","sequence":"additional","affiliation":[{"name":"Department of Physiotherapy, Alma Mater Europaea University, Slovenska Street 17, 2000 Maribor, Slovenia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-9515-3273","authenticated-orcid":false,"given":"Mateusz","family":"Jopek","sequence":"additional","affiliation":[{"name":"Department of Individual and Team Physical Activities, Wroclaw University of Health and Sport Sciences, al. Ignacego Jana Paderewskiego 35, 51-612 Wroc\u0142aw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6750-4316","authenticated-orcid":false,"given":"Krzysztof","family":"Mackala","sequence":"additional","affiliation":[{"name":"Department of Individual and Team Physical Activities, Wroclaw University of Health and Sport Sciences, al. Ignacego Jana Paderewskiego 35, 51-612 Wroc\u0142aw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"853","DOI":"10.1136\/bjsports-2016-096278","article-title":"2016 Consensus statement on return to sport from the First World Congress in Sports Physical Therapy, Bern","volume":"50","author":"Ardern","year":"2016","journal-title":"Br. J. 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