{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,13]],"date-time":"2026-05-13T16:50:00Z","timestamp":1778691000154,"version":"3.51.4"},"reference-count":46,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,11,17]],"date-time":"2025-11-17T00:00:00Z","timestamp":1763337600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012166","name":"National Key R&D Program of China","doi-asserted-by":"publisher","award":["2024YFC3607305"],"award-info":[{"award-number":["2024YFC3607305"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Zhejiang Province Science Fund for Distinguished Young Scholars","award":["LR22A020002"],"award-info":[{"award-number":["LR22A020002"]}]},{"name":"Zhejiang Provincial Key Project of Education Science Planning","award":["2025SB084"],"award-info":[{"award-number":["2025SB084"]}]},{"name":"Ningbo Key Research and Development Program","award":["2022Z196"],"award-info":[{"award-number":["2022Z196"]}]},{"name":"Zhejiang Rehabilitation Medical Association Scientific Research Special Fund","award":["ZKKY2023001"],"award-info":[{"award-number":["ZKKY2023001"]}]},{"name":"Research Academy of Medicine Combining Sports, Ningbo","award":["2023001"],"award-info":[{"award-number":["2023001"]}]},{"name":"Ningbo Clinical Research Center for Orthopedics and Exercise Rehabilitation","award":["2024L004"],"award-info":[{"award-number":["2024L004"]}]},{"DOI":"10.13039\/100007834","name":"Ningbo Natural Science Foundation","doi-asserted-by":"publisher","award":["2022J065"],"award-info":[{"award-number":["2022J065"]}],"id":[{"id":"10.13039\/100007834","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Bioengineering"],"abstract":"<jats:p>Background: Running is a widely practiced physical activity but carries a high risk of injury, with foot structure, particularly the medial arch, playing a vital role in biomechanical performance and injury prevention. As the core of foot support, the arch is essential for absorbing impact, transmitting force, and maintaining dynamic stability. This study aims to compare the dynamic stability of runners with moderate flatfoot and those with normal arches in the initial, steady, and fatigue stages in order to elucidate how fatigue differently affects their dynamic postural control. Methods: Twelve male runners were recruited. Using inertial measurement units (IMUs) and a Zebris treadmill system, data on Maximum Lyapunov Exponent(MLE) and plantar center of pressure (COP) trajectories were collected during the initial, steady-state, and fatigued phases. Results: In the fatigue phase, runners with flatfoot showed an increase of 0.05 s\u22121 in short-term MLE compared to those with normal arches (p &lt; 0.05), indicating significantly lower stability under fatigue. Conclusions: The deterioration of lower-limb dynamic stability in flatfoot runners is dependent on fatigue. Specifically, their overall lower dynamic stability stems primarily from a marked increase in MLE when entering the fatigued phase. Concurrently, fatigue induces alterations in COP trajectory and temporal gait parameters in flatfoot runners; they signify reduced efficiency in gait control.<\/jats:p>","DOI":"10.3390\/bioengineering12111256","type":"journal-article","created":{"date-parts":[[2025,11,17]],"date-time":"2025-11-17T14:04:07Z","timestamp":1763388247000},"page":"1256","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Impact of Fatigue on Spine Dynamic Stability and Gait Patterns in Runners with Moderate Flatfoot Versus Normal Arch"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-5576-2846","authenticated-orcid":false,"given":"Zihang","family":"Xu","sequence":"first","affiliation":[{"name":"Faculty of Sports Science, Ningbo University, Ningbo 315211, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4345-8201","authenticated-orcid":false,"given":"Zixiang","family":"Gao","sequence":"additional","affiliation":[{"name":"Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-4072-7247","authenticated-orcid":false,"given":"Zhanyi","family":"Zhou","sequence":"additional","affiliation":[{"name":"Faculty of Sports Science, Ningbo University, Ningbo 315211, China"},{"name":"Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, 18071 Granada, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-1962-4147","authenticated-orcid":false,"given":"Yucheng","family":"Wang","sequence":"additional","affiliation":[{"name":"Faculty of Sports Science, Ningbo University, Ningbo 315211, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jianqi","family":"Pan","sequence":"additional","affiliation":[{"name":"Faculty of Sports Science, Ningbo University, Ningbo 315211, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Liangliang","family":"Xiang","sequence":"additional","affiliation":[{"name":"KTH MoveAbility Lab, Department of Engineering Mechanics, KTH Royal Institute of Technology, 114 28 Stockholm, Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7438-6290","authenticated-orcid":false,"given":"Yang","family":"Song","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Hong Kong 999077, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7634-5668","authenticated-orcid":false,"given":"Dong","family":"Sun","sequence":"additional","affiliation":[{"name":"Faculty of Sports Science, Ningbo University, Ningbo 315211, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1297-6804","authenticated-orcid":false,"given":"Zsolt","family":"Radak","sequence":"additional","affiliation":[{"name":"Research Institute of Sport Science, Hungarian University of Sport Science, 1123 Budapest, Hungary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4189-7670","authenticated-orcid":false,"given":"Xuanzhen","family":"Cen","sequence":"additional","affiliation":[{"name":"Faculty of Sports Science, Ningbo University, Ningbo 315211, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"E271","DOI":"10.1097\/01.brs.0000216445.28943.d1","article-title":"Stability of dynamic trunk movement","volume":"31","author":"Granata","year":"2006","journal-title":"Spine"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"625","DOI":"10.1249\/MSS.0000000000000436","article-title":"Influence of trunk posture on lower extremity energetics during running","volume":"47","author":"Teng","year":"2015","journal-title":"Med. 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