{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,20]],"date-time":"2026-01-20T02:46:04Z","timestamp":1768877164281,"version":"3.49.0"},"reference-count":30,"publisher":"Public Library of Science (PLoS)","issue":"1","license":[{"start":{"date-parts":[[2025,1,24]],"date-time":"2025-01-24T00:00:00Z","timestamp":1737676800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100020785","name":"United States Army Futures Command","doi-asserted-by":"publisher","award":["W911NF-22-C-0011"],"award-info":[{"award-number":["W911NF-22-C-0011"]}],"id":[{"id":"10.13039\/100020785","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"\nPurpose<\/jats:title>\nTo assess physiological metrics during the use of a commercially available bilateral active ankle exoskeleton during a challenging military-relevant task and if use of the exoskeleton during this task influences: metabolic load, physiological measures or rate of perceived exertion.<\/jats:p>\n<\/jats:sec>\n\nMethods<\/jats:title>\nNine healthy volunteers (5M, 4F) completed this randomized cross-over design trial, with a baseline visit and two randomized test sessions (with\/without the exoskeleton). Variables included impact on time to exhaustion during walking on a treadmill at varying speeds and gradients (0\u201315%) at 26.7\u00b0C, 50% humidity with a loaded rucksack (30% body weight). The primary outcome measure was change in metabolic cost with\/without the exoskeleton (O2 consumption, metabolic equivalents); secondary outcomes were change in heart rate and perceived exertion between conditions.<\/jats:p>\n<\/jats:sec>\n\nResults<\/jats:title>\nParticipants averaged 22.4 \u00b1 4.5 years old, 173.7 \u00b1 7.4 cm tall, weighed 80.9 \u00b1 13.9 kg, and VO2<\/jats:sub>max of 43.8 \u00b1 10.6 mL\/kg\/min. Total kcals did not differ between conditions (with\/without exoskeleton; t = 0.98; p = 0.357). Kcals\/min were significantly lower (1.06 kcals\/min) with the exoskeleton (t = 3.94; p = 0.004). Average oxygen consumption (VO2) was significantly lower (2.36 mL\/kg\/min) with the exoskeleton (t = 2.81; p = 0.023), and peak VO2 was 3.33 mL\/kg\/min lower with the exoskeleton (t = 2.37; p = 0.045). Peak and Average METS were also lower with the exoskeleton by 0.98 (t = 2.61; p = 0.031) and 1.23 (t = 2.39; p = 0.044) respectively.<\/jats:p>\n<\/jats:sec>\n\nConclusions<\/jats:title>\nResults suggest a powered ankle exoskeleton may decrease energy consumption during military relevant tasks when conducted in a laboratory environment. There may also be physiological benefits such as reduced core temperate and heart rate. Replication of this work in the field environment is warranted.<\/jats:p>\n<\/jats:sec>","DOI":"10.1371\/journal.pone.0314613","type":"journal-article","created":{"date-parts":[[2025,1,24]],"date-time":"2025-01-24T18:32:11Z","timestamp":1737743531000},"page":"e0314613","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":3,"title":["The impact of a commercial lower extremity exoskeleton on metabolic load, perceived exertion, and physiological response to a challenging military relevant task: A randomized cross-over design pilot study"],"prefix":"10.1371","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5827-0586","authenticated-orcid":true,"given":"JoEllen M.","family":"Sefton","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Frances K.","family":"Neal","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Philip J.","family":"Agostinelli","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nicholas C.","family":"Bordonie","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Phillip E.","family":"Whitley","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5676-7989","authenticated-orcid":true,"given":"Nathan T.","family":"Pickle","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3027-3432","authenticated-orcid":true,"given":"Paulien E.","family":"Roos","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2025,1,24]]},"reference":[{"issue":"3\u20134","key":"pone.0314613.ref001","first-page":"199","article-title":"Design, Evaluation, and Research Challenges Relevant to Exoskeletons and Exosuits: A 26-Year Perspective From the U.S. Army Research Laboratory.","volume":"7","author":"HP Crowell","year":"2019","journal-title":"Iise T Occup Erg Hum"},{"issue":"5","key":"pone.0314613.ref002","article-title":"Concept design of hybrid-actuated lower limb exoskeleton to reduce the metabolic cost of walking with heavy loads.","volume":"18","author":"QL Meng","year":"2023","journal-title":"Plos One."},{"issue":"10","key":"pone.0314613.ref003","doi-asserted-by":"crossref","first-page":"941","DOI":"10.1038\/s41551-020-00619-3","article-title":"Design and clinical implementation of an open-source bionic leg.","volume":"4","author":"AF Azocar","year":"2020","journal-title":"Nat Biomed Eng"},{"key":"pone.0314613.ref004","first-page":"111","article-title":"Design and Characterization of an Open-source Robotic Leg Prosthesis.","author":"AF Azocar","year":"2018","journal-title":"P Ieee Ras-Embs Int"},{"issue":"7","key":"pone.0314613.ref005","doi-asserted-by":"crossref","first-page":"823","DOI":"10.1109\/TNSRE.2017.2699867","article-title":"Design and Characterization of a Quasi-Passive Pneumatic Foot-Ankle Prosthesis.","volume":"25","author":"JD Lee","year":"2017","journal-title":"Ieee T Neur Sys Reh."},{"issue":"3","key":"pone.0314613.ref006","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1155\/2014\/585837","article-title":"Design considerations of a lower limb exoskeleton system to assist walking and load-carrying of infantry soldiers.","volume":"11","author":"S Yu","year":"2014","journal-title":"Applied Bionics and Biomechanics"},{"key":"pone.0314613.ref007","first-page":"1611","article-title":"Design and Characterization of a Biologically Inspired Quasi-Passive Prosthetic Ankle-Foot.","author":"LM Mooney","year":"2014","journal-title":"Ieee Eng Med Bio."},{"key":"pone.0314613.ref008","first-page":"6","article-title":"Exoskeletons and orthoses: classification, design challenges and future directions","author":"H. 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