{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,24]],"date-time":"2026-06-24T16:01:05Z","timestamp":1782316865965,"version":"3.54.5"},"reference-count":27,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2025,6,29]],"date-time":"2025-06-29T00:00:00Z","timestamp":1751155200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biomimetics"],"abstract":"<jats:p>Piano-based occupational therapy has emerged as an engaging and effective rehabilitation strategy for improving upper limb motor functions. However, a lack of comprehensive biomechanical modeling, objective rehabilitation assessment, and real-time fatigue monitoring has limited its clinical optimization. This study developed a comprehensive \u201ckey\u2013finger\u2013exoskeleton\u201d biomechanical model based on Hill-type muscle dynamics and rigid-body kinematics. A three-dimensional muscle synergy analysis method using non-negative tensor factorization (NTF) was proposed to quantitatively assess rehabilitation effectiveness. Furthermore, a real-time Comprehensive Muscle Fatigue Index (CMFI) based on multi-muscle coordination was designed for fatigue monitoring during therapy. Experimental validations demonstrated that the biomechanical model accurately predicted interaction forces during piano-playing tasks. After three weeks of therapy, patients exhibited increased synergy modes and significantly improved similarities with healthy subjects across spatial, temporal, and frequency domains, particularly in the temporal domain. The CMFI showed strong correlation (r &gt; 0.83, p &lt; 0.001) with subjective fatigue ratings, confirming its effectiveness in real-time fatigue assessment and training adjustment. The integration of biomechanical modeling, synergy-based rehabilitation evaluation, and real-time fatigue monitoring offers an objective, quantitative framework for optimizing piano-based rehabilitation. These findings provide important foundations for developing intelligent, adaptive rehabilitation systems.<\/jats:p>","DOI":"10.3390\/biomimetics10070419","type":"journal-article","created":{"date-parts":[[2025,6,30]],"date-time":"2025-06-30T12:10:31Z","timestamp":1751285431000},"page":"419","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Biomechanical Modeling, Muscle Synergy-Based Rehabilitation Assessment, and Real-Time Fatigue Monitoring for Piano-Integrated Upper Limb Therapy"],"prefix":"10.3390","volume":"10","author":[{"given":"Xin","family":"Zhao","sequence":"first","affiliation":[{"name":"School of Arts and Design, Yanshan University, Haigang District, Qinhuangdao 066000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ying","family":"Zhang","sequence":"additional","affiliation":[{"name":"Arts Department of Qinhuangdao Vocational and Technical College, Beidaihe District, Qinhuangdao 066100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yi","family":"Zhang","sequence":"additional","affiliation":[{"name":"Organization and Publicity Office of the CPC Qinhuangdao Vocational and Technical College Committee, Beidaihe District, Qinhuangdao 066100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shuo","family":"Jiang","sequence":"additional","affiliation":[{"name":"Department of Design, Kyungpook National University, Daegu 41566, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peng","family":"Zhang","sequence":"additional","affiliation":[{"name":"Department of Design, Kyungpook National University, Daegu 41566, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jinxu","family":"Yu","sequence":"additional","affiliation":[{"name":"College of Mechanical and Automotive Engineering, Ningbo University of Technology, Ningbo 315211, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shuai","family":"Yuan","sequence":"additional","affiliation":[{"name":"School of Arts and Design, Yanshan University, Haigang District, Qinhuangdao 066000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"103209","DOI":"10.1016\/j.mex.2025.103209","article-title":"A protocol to optimize non-invasive brain stimulation for post-stroke rehabilitation","volume":"14","author":"Juhi","year":"2025","journal-title":"MethodsX"},{"key":"ref_2","first-page":"CD006876","article-title":"Electromechanical and robot-assisted arm training for improving activities of daily living, arm function, and arm muscle strength after stroke","volume":"9","author":"Mehrholz","year":"2018","journal-title":"Cochrane Database Syst. 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