{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,25]],"date-time":"2026-05-25T15:03:04Z","timestamp":1779721384016,"version":"3.53.1"},"reference-count":44,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2026,5,25]],"date-time":"2026-05-25T00:00:00Z","timestamp":1779667200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Beijing Natural Science Foundation, Haidian Joint Fund","award":["L242103"],"award-info":[{"award-number":["L242103"]}]},{"name":"Beijing Natural Science Foundation, Haidian Joint Fund","award":["L252118"],"award-info":[{"award-number":["L252118"]}]},{"name":"Beijing\u2013Tianjin\u2013Hebei Basic Research Cooperation Special Fund","award":["E2024208086"],"award-info":[{"award-number":["E2024208086"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Preliminary estimation of lower-limb motor function is important in rehabilitation research, especially for biomechanical assessment of post-stroke hemiplegic gait. However, subject-specific musculoskeletal modeling in this population is challenging because standard maximum voluntary contraction (MVC) testing is often unsafe or unreliable for normalizing surface electromyography (sEMG) signals. To address this limitation, a normalized correction coefficient was introduced for pathological sEMG preprocessing, and an improved Hill-type muscle model (iHMM) was established to account for submaximal activation conditions. By combining inverse dynamics, static optimization, and a subject-specific lower-limb dynamic model, the proposed framework was used to estimate musculotendon force, knee joint torque, knee joint kinematics, and shank center-of-mass trajectory. In a preliminary validation involving six hemiplegic subjects, the predicted knee joint torques showed moderate to good agreement with the reference results, with correlation coefficients ranging from 0.724 to 0.807 and RMSE values ranging from 3.872 to 7.814 Nm. These preliminary results support the feasibility of the proposed framework for subject-specific biomechanical analysis of the hemiplegic lower extremity and suggest its potential utility in individualized rehabilitation assessment.<\/jats:p>","DOI":"10.3390\/s26113353","type":"journal-article","created":{"date-parts":[[2026,5,25]],"date-time":"2026-05-25T14:10:22Z","timestamp":1779718222000},"page":"3353","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Biomechanical Modeling and Analysis of the Lower-Limb Musculoskeletal System for Hemiplegia: A Pilot Study"],"prefix":"10.3390","volume":"26","author":[{"given":"Kexiang","family":"Li","sequence":"first","affiliation":[{"name":"College of Mechanical and Material Engineering, North China University of Technology, Beijing 100144, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ye","family":"Sun","sequence":"additional","affiliation":[{"name":"College of Mechanical and Material Engineering, North China University of Technology, Beijing 100144, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chuang","family":"Li","sequence":"additional","affiliation":[{"name":"College of Mechanical and Material Engineering, North China University of Technology, Beijing 100144, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tongzan","family":"Guo","sequence":"additional","affiliation":[{"name":"College of Mechanical Engineering, Hebei University of Technology, Tianjin 300401, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hui","family":"Li","sequence":"additional","affiliation":[{"name":"College of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"129","DOI":"10.2340\/16501977-2289","article-title":"Functional electrical stimulation and ankle foot orthoses provide equivalent therapeutic effects on foot drop: A meta-analysis providing direction for future research","volume":"50","author":"Prenton","year":"2018","journal-title":"J. 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