{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,27]],"date-time":"2026-07-27T09:07:13Z","timestamp":1785143233244,"version":"3.55.0"},"reference-count":19,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2026,7,27]],"date-time":"2026-07-27T00:00:00Z","timestamp":1785110400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Background: Shear wave elastography (SWE) and myotonometry are commonly used to assess muscle stiffness, but they reflect different aspects of tissue mechanics. SWE allows layer-specific evaluation, whereas myotonometry captures the response of a broader tissue complex. The contribution of individual layers to MyotonPRO-derived stiffness remains unclear. This study examined the relationship between MyotonPRO stiffness and layer-specific SWE measurements in the tibialis anterior muscle. Methods: In this cross-sectional study, 56 healthy adults were evaluated. Muscle stiffness was assessed using MyotonPRO and SWE across three regions of interest: superficial tissues including skin, subcutaneous tissue, and deep fascia (ROI 1); muscle tissue excluding fascia (ROI 2); and a composite region including all tissues from the skin surface to a depth of 2 cm (ROI 3). Relationships were analyzed using Spearman correlation, multiple linear regression, and Bland\u2013Altman analysis. Results: Moderate but consistent correlations were observed between MyotonPRO stiffness and SWE values in ROI 2 (\u03c1 = 0.516, p &lt; 0.001) and ROI 3 (\u03c1 = 0.550, p &lt; 0.001), whereas no significant association was found in ROI 1. SWE values in ROI 2 and ROI 3 were significant predictors of MyotonPRO stiffness, explaining 38% of the variance. Bland\u2013Altman analysis demonstrated moderate agreement with a systematic bias toward higher MyotonPRO values. Conclusions: MyotonPRO-derived stiffness reflects a composite mechanical response of muscle and surrounding tissues, with the strongest associations observed in regions encompassing both muscle and fascia. These findings highlight the importance of tissue composition and ROI selection in stiffness assessment and may facilitate more accurate interpretation of MyotonPRO measurements in musculoskeletal diagnostics and rehabilitation.<\/jats:p>","DOI":"10.3390\/diagnostics16152346","type":"journal-article","created":{"date-parts":[[2026,7,27]],"date-time":"2026-07-27T08:15:56Z","timestamp":1785140156000},"page":"2346","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Layer-Specific Shear Wave Elastography Reveals the Tissue Origin of MyotonPRO-Derived Muscle Stiffness"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4983-8018","authenticated-orcid":false,"given":"Sebastian","family":"Szajkowski","sequence":"first","affiliation":[{"name":"Faculty of Medical Sciences, Warsaw Medical Academy of Applied Sciences, 8 Rydygiera St., 01-793 Warszawa, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0528-8854","authenticated-orcid":false,"given":"Micha\u0142","family":"Dwornik","sequence":"additional","affiliation":[{"name":"Medical Rehabilitation and Osteopathy Clinic REHApunkt, Traugutta 12 St., 05-820 Piast\u00f3w, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5694-1377","authenticated-orcid":false,"given":"Krzysztof","family":"Suszy\u0144ski","sequence":"additional","affiliation":[{"name":"Department of Sports Medicine and Physiology of Physical Exercise, Faculty of Health Science in Katowice, Medical University of Silesia, 40-055 Katowice, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6181-337X","authenticated-orcid":false,"given":"Jaros\u0142aw","family":"Pasek","sequence":"additional","affiliation":[{"name":"Collegium Medicum im dr W\u0142adys\u0142awa Biega\u0144skiego, Jan D\u0142ugosz University in Cz\u0119stochowa, 13\/15 Armii Krajowej St., 42-200 Cz\u0119stochowa, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"185","DOI":"10.14366\/usg.16053","article-title":"Current status of musculoskeletal application of shear wave elastography","volume":"36","author":"Ryu","year":"2017","journal-title":"Ultrasonography"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2","DOI":"10.14366\/usg.18039","article-title":"Clinical utilization of shear wave elastography in the musculoskeletal system","volume":"38","author":"Davis","year":"2019","journal-title":"Ultrasonography"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"388","DOI":"10.1016\/j.jbmt.2015.12.005","article-title":"Stiffness of resting lumbar myofascia in healthy young subjects quantified using a handheld myotonometer","volume":"20","author":"Nair","year":"2016","journal-title":"J. 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Kinesiol."}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/15\/2346\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,27]],"date-time":"2026-07-27T08:25:29Z","timestamp":1785140729000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/15\/2346"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,27]]},"references-count":19,"journal-issue":{"issue":"15","published-online":{"date-parts":[[2026,8]]}},"alternative-id":["diagnostics16152346"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics16152346","relation":{},"ISSN":["2075-4418"],"issn-type":[{"value":"2075-4418","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,27]]}}}