{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,9]],"date-time":"2026-09-09T05:07:24Z","timestamp":1788930444060,"version":"build-2803163510"},"reference-count":27,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,9,7]],"date-time":"2026-09-07T00:00:00Z","timestamp":1788739200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002457","name":"Chosun University","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100002457","id-type":"DOI","asserted-by":"crossref"}]},{"id":[{"id":"https:\/\/ror.org\/01zt9a375","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Bioengineering"],"abstract":"<jats:p>Walking on a ship requires continuous adaptation to a support surface that changes orientation with vessel motion. However, conventional group-level and joint-by-joint analyses may not characterize the coordinated structure of this adaptation or the heterogeneity of individual responses. This secondary analysis examined multivariate lower-limb joint-angle variability during simulated ship roll in 30 healthy adults completing nine 2-min walking trials across roll amplitudes of 0\u201320\u00b0 and roll periods of 6 and 12 s. OpenSim-derived joint angles were summarized as 28 trial-level variability features. Principal component analysis, k-means clustering, hierarchical density-based spatial clustering of applications with noise (HDBSCAN), and generalized estimating equations were applied. Five principal components explained 78.1% of the total variance, with PC1 alone explaining 53.4% and representing a coordinated increase in lower limb joint angle variability, particularly in the sagittal-plane. k-means derived operational partition classified trials into low- and high-variability groups. The odds of high-variability group membership increased 1.48-fold per 1\u00b0 increase in roll amplitude (p &lt; 0.001), whereas roll period was not significantly associated with group membership (p = 0.704). HDBSCAN showed weak density separation (DBCV = 0.061) and substantial participant-level heterogeneity. These findings highlight the potential value of individualized roll-sensitivity assessment and provide a biomechanical basis for future studies of shipboard gait safety and fall-risk assessment.<\/jats:p>","DOI":"10.3390\/bioengineering13091039","type":"journal-article","created":{"date-parts":[[2026,9,7]],"date-time":"2026-09-07T10:30:46Z","timestamp":1788777046000},"page":"1039","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Multivariate Characterization of Gait Variability Under Simulated Ship Roll Motion"],"prefix":"10.3390","volume":"13","author":[{"given":"Namwoong","family":"Kim","sequence":"first","affiliation":[{"name":"Division of Health and Kinesiology, Incheon National University, Incheon 22012, Republic of Korea"},{"name":"Department of Human Movement Science, Incheon National University, Incheon 22012, Republic of Korea"},{"name":"Sports Science Institute, Incheon National University, Incheon 22012, Republic of Korea"},{"name":"Sports Functional Disability Institute, Incheon National University, Incheon 22012, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Minsu","family":"Song","sequence":"additional","affiliation":[{"name":"Department of Economics, Chosun University, Gwangju 61452, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9612-3029","authenticated-orcid":false,"given":"Jungyeon","family":"Choi","sequence":"additional","affiliation":[{"name":"Department of Computer Science and Statistics, Chosun University, Gwangju 61452, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1002\/ajim.20119","article-title":"Non-fatal occupational injuries related to slips, trips and falls in seafaring","volume":"47","author":"Jensen","year":"2005","journal-title":"Am. 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