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Consequently, active powered prosthetic devices have been developed; however, it is unclear how to optimally tune them. The purpose of this study was to identify the optimal ankle torque profile of a powered ankle\u2013foot prosthesis that improves walking performance for individuals with TTA. Specifically, we used a musculoskeletal simulation-based optimization framework to optimize a powered prosthesis torque profile while emulating group averaged kinematics and ground reaction forces (GRFs). We compared the metabolic cost, knee joint loading, sagittal plane dynamic balance symmetry, and torque profiles across the following simulated conditions: a passive prosthesis tracking individuals with TTA walking data, a powered prosthesis tracking able-bodied walking data, and a powered prosthesis that separately minimized metabolic cost, knee joint loading, and dynamic balance asymmetry. Distinct torque profiles emerged for each measure, but there was no clear trend in the positive prosthetic work performed, which suggests increased prosthetic work alone is insufficient to improve walking performance. Further analysis showed the prosthetic torque must be properly timed over the gait cycle to improve each measure. This study provides a framework for future work developing customized controllers for powered prostheses to improve various aspects of walking performance for individuals with TTA.<\/jats:p>","DOI":"10.1115\/1.4071411","type":"journal-article","created":{"date-parts":[[2026,3,17]],"date-time":"2026-03-17T12:12:11Z","timestamp":1773749531000},"update-policy":"https:\/\/doi.org\/10.1115\/crossmarkpolicy-asme","source":"Crossref","is-referenced-by-count":0,"title":["Optimal Powered Ankle\u2013Foot Prosthesis Torque Profiles to Improve Walking Performance for Individuals With a Unilateral Transtibial Amputation"],"prefix":"10.1115","volume":"148","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-0524-7158","authenticated-orcid":false,"given":"Eric H.","family":"Hu","sequence":"first","affiliation":[{"name":"Walker Department of Mechanical Engineering, The University of Texas at Austin , 204 East Dean Keeton Street , Austin, TX 78712-1591"},{"id":[{"id":"https:\/\/ror.org\/00hj54h04","id-type":"ROR","asserted-by":"publisher"}],"name":"The University of Texas at Austin"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Glenn K.","family":"Klute","sequence":"additional","affiliation":[{"name":"Department of Veterans Affairs, Puget Sound Health Care System , 1660 South Columbian Way, MS-151, Seattle, WA 98118 ; , 3900 East Stevens Way NE , Seattle, WA 98195"},{"name":"Department of Mechanical Engineering, University of Washington , 1660 South Columbian Way, MS-151, Seattle, WA 98118 ; , 3900 East Stevens Way NE , Seattle, WA 98195"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2425-004X","authenticated-orcid":false,"given":"Richard R.","family":"Neptune","sequence":"additional","affiliation":[{"name":"Walker Department of Mechanical Engineering, The University of Texas at Austin , 204 East Dean Keeton Street , Austin, TX 78712-1591"},{"id":[{"id":"https:\/\/ror.org\/00hj54h04","id-type":"ROR","asserted-by":"publisher"}],"name":"The University of Texas at Austin"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"33","published-online":{"date-parts":[[2026,4,8]]},"reference":[{"issue":"1","key":"2026040811343212000_bib1","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1682\/JRRD.2006.11.0147","article-title":"Review of Secondary Physical Conditions Associated With Lower-Limb Amputation and Long-Term Prosthesis Use","volume":"45","year":"2008","journal-title":"J. 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