{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,6]],"date-time":"2026-10-06T22:54:06Z","timestamp":1791327246541,"version":"4.3.1"},"reference-count":55,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T00:00:00Z","timestamp":1768176000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Bioengineering"],"abstract":"<jats:p>Aim: This study examined how load size and symmetry affect trunk muscle activation patterns, vertical ground reaction forces, and estimated lumbar spine compression during overground walking in individuals with chronic low back pain (CLBP) and those without symptoms. Methods: Thirty male participants (15 with CLBP, 15 controls; ages 23\u201328 years) performed walking tests under four load conditions: symmetric and asymmetric carriage at 10% and 20% of body weight. Bilateral surface electromyography measured activation from seven trunk muscles (rectus abdominis, external oblique, internal oblique, latissimus dorsi, lumbar erector spinae, multifidus) and the thoracolumbar fascia region, normalized to maximum voluntary isometric contractions (%MVIC). Force plates recorded vertical ground reaction forces synchronized with heel-strike events. A repeated-measures ANOVA with Bonferroni corrections was used to analyze the effects of load configuration and magnitude. Results: Asymmetric loading at 20% body weight caused significantly higher peak vertical ground reaction forces compared to symmetric loading (mean difference = 47.3 N, p &lt; 0.001), with a significant interaction between load magnitude and configuration (p = 0.004, \u03b7p2 = 0.26). Participants with CLBP showed consistently higher trunk muscle activation throughout the gait cycle (peak: 37% MVIC vs. 30% MVIC in controls; p &lt; 0.001, d = 1.68), with maximum recruitment at shorter muscle lengths and 24% less activation at optimal length (95% CI: 18.2\u201329.8%). The lumbar erector spinae and multifidus muscles exhibited the highest activation during asymmetric 20% loading in CLBP participants (0.282 and 0.263%MVIC, respectively), indicating compensatory neuromuscular strategies. Conclusion: Asymmetric load carriage creates disproportionately high mechanical and neuromuscular demands, effects that are greatly amplified in individuals with CLBP. These findings support rehabilitation strategies that improve load distribution and restore motor control, thereby reducing compensatory strain and enhancing trunk stability.<\/jats:p>","DOI":"10.3390\/bioengineering13010082","type":"journal-article","created":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T12:44:44Z","timestamp":1768221884000},"page":"82","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Neuromuscular and Kinetic Adaptations to Symmetric and Asymmetric Load Carriage During Walking in Individuals with Chronic Low Back Pain"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-6266-3974","authenticated-orcid":false,"given":"Raheleh","family":"Tajik","sequence":"first","affiliation":[{"name":"Department of Biomechanics and Sports Injury, Kharazmi University, Tehran 31979-37551, Iran"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6221-546X","authenticated-orcid":false,"given":"Wissem","family":"Dhahbi","sequence":"additional","affiliation":[{"name":"Research Unit (UR22JS01) \u201cSport Sciences, Health and Movement\u201d, High Institute of Sport and Physical Education of Kef, University of Jendouba, Le Kef 7100, Tunisia"},{"name":"Training Department, Police College, Qatar Police Academy, Doha 7157, Qatar"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0558-6421","authenticated-orcid":false,"given":"Raghad","family":"Mimar","sequence":"additional","affiliation":[{"name":"Department of Biomechanics and Sports Injury, Kharazmi University, Tehran 31979-37551, Iran"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mehdi","family":"Khaleghi Tazji","sequence":"additional","affiliation":[{"name":"Department of Biomechanics and Sports Injury, Kharazmi University, Tehran 31979-37551, Iran"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-2214-4667","authenticated-orcid":false,"given":"Halil \u0130brahim","family":"Ceylan","sequence":"additional","affiliation":[{"name":"Faculty of Sports Sciences, Atat\u00fcrk University, Erzurum 25240, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2166-6675","authenticated-orcid":false,"given":"Serdar","family":"Bayrakdaro\u011flu","sequence":"additional","affiliation":[{"name":"Faculty of Sports Sciences, G\u00fcm\u00fc\u015fhane University, Gumushane 29100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4031-1412","authenticated-orcid":false,"given":"Valentina","family":"Stefanica","sequence":"additional","affiliation":[{"name":"Department of Physical Education and Sport, Faculty of Sciences, Physical Education and Informatics, National University of Science and Technology Politehnica Bucharest, Pitesti University Center, 060042 Pitesti, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5256-2887","authenticated-orcid":false,"given":"Nadhir","family":"Hammami","sequence":"additional","affiliation":[{"name":"Research Unit (UR22JS01) \u201cSport Sciences, Health and Movement\u201d, High Institute of Sport and Physical Education of Kef, University of Jendouba, Le Kef 7100, Tunisia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"299","DOI":"10.21037\/atm.2020.02.175","article-title":"Global low back pain prevalence and years lived with disability from 1990 to 2017: Estimates from the Global Burden of Disease Study 2017","volume":"8","author":"Wu","year":"2020","journal-title":"Ann. 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