{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T03:07:02Z","timestamp":1785467222504,"version":"3.56.0"},"reference-count":49,"publisher":"Public Library of Science (PLoS)","issue":"1","license":[{"start":{"date-parts":[[2025,1,2]],"date-time":"2025-01-02T00:00:00Z","timestamp":1735776000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"publisher","award":["316739714"],"award-info":[{"award-number":["316739714"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:p>Prosthetic gait differs considerably from the unimpaired gait. Studying alterations in the gait patterns could help to understand different adaptation mechanisms adopted by these populations. This study investigated the effects of induced stiff-knee gait (SKG) on prosthetic and healthy gait patterns and the capabilities of predictive simulation. Self-selected speed gait of two participants was measured: one healthy subject and one knee disarticulation subject using a variable-damping microprocessor controlled knee prosthesis. Both performed unperturbed gait and gait with restricted knee flexion. Experimental joint angles and moments were computed using OpenSim and muscle activity was measured using surface electromyography (EMG). The differences between the conditions were analyzed using statistical parametric mapping (SPM). Predictive models based on optimal control were created to represent the participants. Additionally, a hypothetical unimpaired predictive model with the same anthropometric characteristics as the amputee was created. Some patterns observed in the experimental prosthetic gait were predicted by the models, including increased knee flexion moment on the contralateral side caused by SKG in both participants, which was statistically significant according to SPM. With the exception of the rectus femoris muscle, we also found overall good agreement between measured EMG and predicted muscle activation. We predicted more alterations in activation of the hip flexors than other muscle groups due to the amputation and in the activation of the biceps femoris short head, quadratus femoris, and tibialis anterior due to SKG. In summary, we demonstrated that the method applied in this study could predict gait alterations due to amputation of the lower limb or due to imposed SKG.<\/jats:p>","DOI":"10.1371\/journal.pone.0314758","type":"journal-article","created":{"date-parts":[[2025,1,2]],"date-time":"2025-01-02T19:21:23Z","timestamp":1735845683000},"page":"e0314758","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":3,"title":["Predicting prosthetic gait and the effects of induced stiff-knee gait"],"prefix":"10.1371","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-7731-084X","authenticated-orcid":true,"given":"Gilmar F.","family":"Santos","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eike","family":"Jakubowitz","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christof","family":"Hurschler","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2025,1,2]]},"reference":[{"issue":"1","key":"pone.0314758.ref001","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1177\/0309364610389357","article-title":"Prevalence of back pain, its effect on functional ability and health-related quality of life in lower limb amputees secondary to trauma or tumour: a comparison across three levels of amputation","volume":"35","author":"CS Hammarlund","year":"2011","journal-title":"Prosthet Orthot Int"},{"issue":"10","key":"pone.0314758.ref002","doi-asserted-by":"crossref","first-page":"1144","DOI":"10.1111\/j.1464-5491.2011.03279.x","article-title":"Lower extremity amputations\u2014a review of global variability in incidence","volume":"28","author":"PW Moxey","year":"2011","journal-title":"Diabet Med"},{"issue":"3","key":"pone.0314758.ref003","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1682\/JRRD.2011.10.0187","article-title":"Outcomes associated with the use of microprocessor-controlled prosthetic knees among individuals with unilateral transfemoral limb loss: a systematic review","volume":"50","author":"AB Sawers","year":"2013","journal-title":"J Rehabil Res Dev"},{"issue":"5","key":"pone.0314758.ref004","doi-asserted-by":"crossref","first-page":"460","DOI":"10.1016\/j.clinbiomech.2011.11.011","article-title":"Gait asymmetry of transfemoral amputees using mechanical and microprocessor-controlled prosthetic knees.","volume":"27","author":"KR Kaufman","year":"2012","journal-title":"Clinical Biomechanics."},{"issue":"4","key":"pone.0314758.ref005","doi-asserted-by":"crossref","first-page":"644","DOI":"10.1016\/j.apmr.2009.12.014","article-title":"Comparative biomechanical analysis of current microprocessor-controlled prosthetic knee joints","volume":"91","author":"M Bellmann","year":"2010","journal-title":"Arch Phys Med Rehabil"},{"issue":"1","key":"pone.0314758.ref006","first-page":"119","article-title":"Designs and performance of three new microprocessor-controlled knee joints.","volume":"64","author":"J Thiele","year":"2019","journal-title":"Biomed Tech (Berl)"},{"issue":"8","key":"pone.0314758.ref007","doi-asserted-by":"crossref","first-page":"563","DOI":"10.1097\/01.phm.0000174665.74933.0b","article-title":"A clinical comparison of variable-damping and mechanically passive prosthetic knee devices","volume":"84","author":"JL Johansson","year":"2005","journal-title":"American Journal of Physical Medicine & Rehabilitation"},{"issue":"1","key":"pone.0314758.ref008","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1108\/01439910310457706","article-title":"User\u2010adaptive control of a magnetorheological prosthetic knee.","volume":"30","author":"H Herr","year":"2003","journal-title":"Industrial Robot."},{"issue":"6","key":"pone.0314758.ref009","doi-asserted-by":"crossref","first-page":"1055","DOI":"10.1016\/j.jbiomech.2009.12.012","article-title":"Optimality principles for model-based prediction of human gait","volume":"43","author":"M Ackermann","year":"2010","journal-title":"J Biomech"},{"issue":"157","key":"pone.0314758.ref010","doi-asserted-by":"crossref","first-page":"20190402","DOI":"10.1098\/rsif.2019.0402","article-title":"Rapid predictive simulations with complex musculoskeletal models suggest that diverse healthy and pathological human gaits can emerge from similar control strategies.","volume":"16","author":"A Falisse","year":"2019","journal-title":"J R Soc Interface."},{"key":"pone.0314758.ref011","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1016\/j.gaitpost.2016.07.007","article-title":"Joint contact forces can be reduced by improving joint moment symmetry in below-knee amputee gait simulations.","volume":"49","author":"AD Koelewijn","year":"2016","journal-title":"Gait Posture"},{"key":"pone.0314758.ref012","doi-asserted-by":"crossref","unstructured":"Price MA, Umberger BR, Sup FC. Dynamic optimization of gait with a generalized lower-limb prosthesis model. In: 2019 IEEE 16th International Conference on Rehabilitation Robotics (ICORR) [Internet]. Toronto, ON, Canada: IEEE; 2019 [cited 2020 Dec 3]. p. 734\u20139. 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