{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T18:19:37Z","timestamp":1785435577356,"version":"3.56.0"},"reference-count":38,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,6,24]],"date-time":"2026-06-24T00:00:00Z","timestamp":1782259200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001840","name":"Icelandic Center for Research","doi-asserted-by":"crossref","award":["2215370-0611"],"award-info":[{"award-number":["2215370-0611"]}],"id":[{"id":"10.13039\/501100001840","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100005415","name":"University of Iceland Research Fund","doi-asserted-by":"publisher","award":["RSJ2025-96411"],"award-info":[{"award-number":["RSJ2025-96411"]}],"id":[{"id":"10.13039\/501100005415","id-type":"DOI","asserted-by":"publisher"}]},{"award":["RSJ2025-96411"],"award-info":[{"award-number":["RSJ2025-96411"]}],"id":[{"id":"https:\/\/ror.org\/01db6h964","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Bioengineering"],"abstract":"<jats:p>This study investigated the feasibility and biomechanical effects of volitional electromyography (EMG)-based control of a powered transtibial ankle prosthesis. Four male participants completed static and dynamic EMG assessments and gait analysis while using both their prescribed passive prosthesis and an EMG-controlled powered prototype during level walking at self-selected and fast speeds, as well as ramp ascent and descent. Selective activation of residual tibialis anterior and gastrocnemius muscles was quantified using a co-contraction index, and lower-limb kinematics and kinetics were compared between prosthetic conditions. Participants were able to generate task-dependent residual muscle activity, supporting the feasibility of EMG-based volitional control. However, muscle selectivity was reduced during dynamic tasks, with higher co-contraction during gait than during seated static contractions, and substantial inter-subject variability was observed. Compared to the prescribed passive prosthesis, the EMG-controlled prototype generally produced lower prosthetic-side ankle range of motion and ankle power, although ankle moments were sometimes slightly greater. These findings suggest that EMG control is feasible, but that future controller design must remain flexible to individual users\u2019 neuromuscular abilities and dynamic control limitations. The results provide important guidance for the development and testing of more adaptive, personalized, and functionally effective EMG-controlled prosthetic ankle systems.<\/jats:p>","DOI":"10.3390\/bioengineering13070722","type":"journal-article","created":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T15:02:56Z","timestamp":1783436576000},"page":"722","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Volitional EMG Control of a Novel Powered Ankle Prosthesis: A Case Series on Muscle Selectivity and Biomechanical Consequences"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-3409-3092","authenticated-orcid":false,"given":"Faranak","family":"Rostamjoud","sequence":"first","affiliation":[{"name":"School of Health Sciences, University of Iceland, 102 Reykjav\u00edk, Iceland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7486-0212","authenticated-orcid":false,"given":"Mohamed","family":"Abdelbar","sequence":"additional","affiliation":[{"name":"School of Engineering and Natural Sciences, University of Iceland, 102 Reykjav\u00edk, Iceland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fri\u00f0rika Bj\u00f6rk","family":"\u00deorkelsd\u00f3ttir","sequence":"additional","affiliation":[{"name":"\u00d6ssur Ehf., Grjothals 1\u20135, 110 Reykjav\u00edk, Iceland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sophie","family":"Thiele","sequence":"additional","affiliation":[{"name":"\u00d6ssur Ehf., Grjothals 1\u20135, 110 Reykjav\u00edk, Iceland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna L\u00e1ra","family":"\u00c1rmannsd\u00f3ttir","sequence":"additional","affiliation":[{"name":"\u00d6ssur Ehf., Grjothals 1\u20135, 110 Reykjav\u00edk, Iceland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2385-9398","authenticated-orcid":false,"given":"Atli \u00d6rn","family":"Sverrisson","sequence":"additional","affiliation":[{"name":"\u00d6ssur Ehf., Grjothals 1\u20135, 110 Reykjav\u00edk, Iceland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9435-2258","authenticated-orcid":false,"given":"Sigur\u00f0ur","family":"Brynj\u00f3lfsson","sequence":"additional","affiliation":[{"name":"School of Engineering and Natural Sciences, University of Iceland, 102 Reykjav\u00edk, Iceland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0606-991X","authenticated-orcid":false,"given":"Krist\u00edn","family":"Briem","sequence":"additional","affiliation":[{"name":"School of Health Sciences, University of Iceland, 102 Reykjav\u00edk, Iceland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"776","DOI":"10.1109\/TNSRE.2014.2356722","article-title":"Mechanisms of Gait Asymmetry Due to Push-Off Deficiency in Unilateral Amputees","volume":"23","author":"Adamczyk","year":"2015","journal-title":"IEEE Trans. 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