{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T20:07:01Z","timestamp":1790798821714,"version":"4.1.0"},"reference-count":55,"publisher":"Public Library of Science (PLoS)","issue":"9","license":[{"start":{"date-parts":[[2025,9,4]],"date-time":"2025-09-04T00:00:00Z","timestamp":1756944000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Harvard Move Lab","award":["Harvard Move Lab"],"award-info":[{"award-number":["Harvard Move Lab"]}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>Accurately estimating kinetic metrics, such as braking and propulsion forces, in real-world running environments enhances our understanding of performance, fatigue, and injury. Wearable inertial measurement units (IMUs) offer a potential solution to estimate kinetic metrics outside the lab when combined with machine learning. However, current IMU-based kinetic estimation models are trained and evaluated within a single environment, often on lab treadmills. The transferability of these treadmill-trained models during overground running in and out of the lab is underexplored, and the individualization and validation of such models remain a challenge. Toward bridging this gap, we trained a generalized model on treadmill data of 15 recreational runners and evaluated braking and propulsion force estimates during overground running in and out of the lab. We explored fine-tuning with individual data from lab-based overground running to quantify model performance improvements with individualization. The generalized and fine-tuned models were extrapolated to outdoor running for a subset of five participants, and estimates were compared to lab-based overground measurements. Evaluating the generalized model with a leave-one-out cross validation yielded overground braking and propulsion force root mean squared error of 4.3 \u00b1 1.1 % bodyweight (%BW). Fine-tuning this model with eight strides reduced error to 2.6 \u00b1 0.5 %BW. Outdoor force predictions from the fine-tuned model better aligned with expected linear trends between braking\/propulsion impulses and speed than the generalized model. These results provide insights into the accuracy and applicability of IMU data-driven models for braking and propulsion estimation during overground running, facilitating the development of practical, individualized biomechanical analysis tools for real-world use.<\/jats:p>","DOI":"10.1371\/journal.pone.0330042","type":"journal-article","created":{"date-parts":[[2025,9,4]],"date-time":"2025-09-04T17:50:27Z","timestamp":1757008227000},"page":"e0330042","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":4,"title":["Estimating braking and propulsion forces during overground running in and out of the lab"],"prefix":"10.1371","volume":"20","author":[{"given":"Lauren M.","family":"Baker","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fabian C.","family":"Weigend","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Krithika","family":"Swaminathan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7777-8388","authenticated-orcid":true,"given":"Daekyum","family":"Kim","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-9523-6097","authenticated-orcid":true,"given":"Andrew","family":"Chin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel E.","family":"Lieberman","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2744-917X","authenticated-orcid":true,"given":"Conor J.","family":"Walsh","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2025,9,4]]},"reference":[{"issue":"3","key":"pone.0330042.ref001","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1136\/bjsm.37.3.239","article-title":"A prospective study of running injuries: the Vancouver Sun Run \u201cIn Training\u201d clinics","volume":"37","author":"JE Taunton","year":"2003","journal-title":"Br J Sports Med."},{"issue":"5","key":"pone.0330042.ref002","doi-asserted-by":"crossref","first-page":"1722","DOI":"10.3390\/s22051722","article-title":"Is this the real life, or is this just laboratory? 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