{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T18:11:54Z","timestamp":1790187114360,"version":"4.1.0"},"reference-count":57,"publisher":"American Association for the Advancement of Science (AAAS)","issue":"118","funder":[{"name":"Linda J. and Mark C. Smith Chair Funding"}],"content-domain":{"domain":["www.science.org"],"crossmark-restriction":true},"short-container-title":["Sci. Robot."],"published-print":{"date-parts":[[2026,9,23]]},"abstract":"<jats:p>Modern assistive robotic control demands parallel advancements in wearable, noninvasive sensing. Electrical impedance myography (EIM)\u2014a noninvasive, wearable technology for dynamically measuring tissue electrical impedance properties\u2014is a promising but poorly established solution for quantifying muscle force and fatigue, given that prior approaches have relied on black-box algorithms when attempting to relate EIM to muscle physiology or have extrapolated relationships between EIM and muscle force from singular, isolated movements. Here, we elucidate direct relationships between EIM and muscle kinematics and kinetics during functional movement using biomechanical principles and traditional measures of joint torque, muscle architecture, and activation. Dual-frequency EIM measurements of the medial gastrocnemius of 10 participants were collected and compared against dynamometer, B-mode ultrasound, and electromyography measurements. Participants performed multiple categories of dynamic movements spanning constrained isometric, self-selected isometric, concentric, and eccentric contractions at multiple force levels, joint angles, and angular velocities. EIM correlated to joint torque only for specific conditions, whereas EIM correlated with muscle length change dynamics across all movements. Mixed-effects modeling and sequential feature analysis showed fascicle length and muscle activation as primary drivers of EIM variance. Last, dual-frequency EIM combined with principal components analysis reliably captured changes in fascicle length and activation during walking. These findings validate EIM as a robust, real-time biomechanical tool for sensing muscle kinematics and neuromuscular activity during functional movement, expanding its use in assistive robotic control and injury prevention.<\/jats:p>","DOI":"10.1126\/scirobotics.aea4580","type":"journal-article","created":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T17:58:37Z","timestamp":1790186317000},"update-policy":"https:\/\/doi.org\/10.34133\/aaas_crossmark","source":"Crossref","is-referenced-by-count":0,"title":["Bioimpedance meets biomechanics: Wearable electrical impedance myography encodes fascicle and activation dynamics"],"prefix":"10.1126","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3114-6681","authenticated-orcid":true,"given":"Christopher J.","family":"Nichols","sequence":"first","affiliation":[{"name":"School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-8727-7124","authenticated-orcid":true,"given":"Nicholas","family":"Harris","sequence":"additional","affiliation":[{"name":"School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1727-402X","authenticated-orcid":true,"given":"H. Trask","family":"Crane","sequence":"additional","affiliation":[{"name":"School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-3183-9448","authenticated-orcid":true,"given":"Autumn","family":"Routt","sequence":"additional","affiliation":[{"name":"School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-5986-0792","authenticated-orcid":true,"given":"Milki D.","family":"Haile","sequence":"additional","affiliation":[{"name":"School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3853-5495","authenticated-orcid":true,"given":"Quentin","family":"Goossens","sequence":"additional","affiliation":[{"name":"School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9260-0366","authenticated-orcid":true,"given":"Minoru","family":"Shinohara","sequence":"additional","affiliation":[{"name":"Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, USA."},{"name":"School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5588-6297","authenticated-orcid":true,"given":"Gregory S.","family":"Sawicki","sequence":"additional","affiliation":[{"name":"School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA."},{"name":"Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3435-8353","authenticated-orcid":true,"given":"Kristen L.","family":"Jakubowski","sequence":"additional","affiliation":[{"name":"Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, USA."},{"name":"School of Kinesiology, University of Michigan, Ann Arbor, MI, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7952-1794","authenticated-orcid":true,"given":"Omer T.","family":"Inan","sequence":"additional","affiliation":[{"name":"School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA."},{"name":"Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"221","reference":[{"key":"e_1_3_2_2_2","doi-asserted-by":"crossref","unstructured":"J. L. Pons Ed. Wearable Robots: Biomechatronic Exoskeletons (John Wiley & Sons 2008).","DOI":"10.1002\/9780470987667"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.3390\/s23041856"},{"key":"e_1_3_2_4_2","first-page":"2747","article-title":"Wearable sensing for solid biomechanics: A review","volume":"15","author":"Wong C.","year":"2015","unstructured":"C. Wong, Z.-Q. Zhang, B. Lo, G.-Z. Yang, Wearable sensing for solid biomechanics: A review. IEEE Sensors J. 15, 2747\u20132760 (2015).","journal-title":"IEEE Sensors J."},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1186\/s12984-021-00963-8"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41586-024-08157-7"},{"key":"e_1_3_2_7_2","doi-asserted-by":"crossref","unstructured":"J. L. Pons R. Ceres L. Calder\u00f3n \u201cIntroduction to wearable robotics\u201d in Wearable Robots: Biomechatronic Exoskeletons J. L. Pons Ed. (John Wiley & Sons Ltd 2008) pp. 1\u201316.","DOI":"10.1002\/9780470987667.ch1"},{"key":"e_1_3_2_8_2","doi-asserted-by":"publisher","DOI":"10.1039\/C7LC00914C"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1126\/scirobotics.abj1362"},{"key":"e_1_3_2_10_2","doi-asserted-by":"crossref","unstructured":"B. Milosevic E. Farella S. Benatti \u201cExploring arm posture and temporal variability in myoelectric hand gesture recognition\u201d in 2018 7th IEEE International Conference on Biomedical Robotics and Biomechatronics (Biorob) (IEEE 2018) pp. 1032\u20131037.","DOI":"10.1109\/BIOROB.2018.8487838"},{"key":"e_1_3_2_11_2","doi-asserted-by":"crossref","unstructured":"F. Palermo M. Cognolato A. Gijsberts H. M\u00fcller B. Caputo M. Atzori \u201cRepeatability of grasp recognition for robotic hand prosthesis control based on sEMG data\u201d in 2017 International Conference on Rehabilitation Robotics (ICORR) (IEEE 2017) pp. 1154\u20131159.","DOI":"10.1109\/ICORR.2017.8009405"},{"key":"e_1_3_2_12_2","doi-asserted-by":"publisher","DOI":"10.3389\/fnsys.2022.893275"},{"key":"e_1_3_2_13_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0246611"},{"key":"e_1_3_2_14_2","doi-asserted-by":"publisher","DOI":"10.2519\/jospt.2011.3682"},{"key":"e_1_3_2_15_2","doi-asserted-by":"publisher","DOI":"10.21105\/joss.05206"},{"key":"e_1_3_2_16_2","doi-asserted-by":"publisher","DOI":"10.1177\/014860719902300296"},{"key":"e_1_3_2_17_2","doi-asserted-by":"crossref","unstructured":"S. Grimnes \u00d8. G. Martinsen \u201cChapter 4\u2014Passive tissue electrical properties\u201d in Bioimpedance and Bioelectricity Basics S. Grimnes \u00d8. G. Martinsen Eds. (Academic Press ed. 3 2015) pp. 77\u2013118.","DOI":"10.1016\/B978-0-12-411470-8.00004-0"},{"key":"e_1_3_2_18_2","doi-asserted-by":"publisher","DOI":"10.1109\/JSEN.2019.2936171"},{"key":"e_1_3_2_19_2","doi-asserted-by":"publisher","DOI":"10.1109\/OJEMB.2023.3256181"},{"key":"e_1_3_2_20_2","doi-asserted-by":"publisher","DOI":"10.1002\/mus.25559"},{"key":"e_1_3_2_21_2","doi-asserted-by":"publisher","DOI":"10.1109\/TBME.2014.2320132"},{"key":"e_1_3_2_22_2","doi-asserted-by":"publisher","DOI":"10.1109\/TBME.2023.3290530"},{"key":"e_1_3_2_23_2","doi-asserted-by":"publisher","DOI":"10.1109\/ACCESS.2020.2970314"},{"key":"e_1_3_2_24_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jare.2020.05.016"},{"key":"e_1_3_2_25_2","doi-asserted-by":"crossref","unstructured":"G. C. Ozmen C. Nichols S. Mabrouk J. Berkebile L. Lan O. T. Inan \u201cWearable mid-activity measurement of lower limb electrical bioimpedance estimates vertical ground reaction force features\u201d in 44th Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC) (IEEE 2022) pp. 91\u201394.","DOI":"10.1109\/EMBC48229.2022.9871267"},{"key":"e_1_3_2_26_2","doi-asserted-by":"crossref","unstructured":"B. Sanchez J. Li T. Geisbush R. Bragos S. B. Rutkove \u201cA pilot spectroscopy study on time-varying bioimpedance during electrically-induced muscle contraction\u201d in 2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE 2014) pp. 3739\u20133742.","DOI":"10.1109\/EMBC.2014.6944436"},{"key":"e_1_3_2_27_2","doi-asserted-by":"publisher","DOI":"10.1109\/JSEN.2023.3277855"},{"key":"e_1_3_2_28_2","doi-asserted-by":"publisher","DOI":"10.3390\/s22010152"},{"key":"e_1_3_2_29_2","doi-asserted-by":"publisher","DOI":"10.1109\/TBME.2023.3262206"},{"key":"e_1_3_2_30_2","doi-asserted-by":"publisher","DOI":"10.1109\/JSEN.2021.3053434"},{"key":"e_1_3_2_31_2","doi-asserted-by":"publisher","DOI":"10.1088\/1742-6596\/407\/1\/012018"},{"key":"e_1_3_2_32_2","doi-asserted-by":"publisher","DOI":"10.1109\/TBME.2019.2927807"},{"key":"e_1_3_2_33_2","unstructured":"Analog Devices \u201cAD5940 datasheet and product info\u201d; www.analog.com\/en\/products\/ad5940.html#product-overview."},{"key":"e_1_3_2_34_2","doi-asserted-by":"publisher","DOI":"10.1109\/JSEN.2021.3128555"},{"key":"e_1_3_2_35_2","doi-asserted-by":"publisher","DOI":"10.1109\/TBME.2016.2641958"},{"key":"e_1_3_2_36_2","doi-asserted-by":"publisher","DOI":"10.1186\/s12984-015-0081-x"},{"key":"e_1_3_2_37_2","doi-asserted-by":"publisher","DOI":"10.3390\/bios14020076"},{"key":"e_1_3_2_38_2","doi-asserted-by":"crossref","unstructured":"O. L. Silva T. H. S. Sousa I. O. Hoffman E. D. L. B. de Camargo F. S. de Moura A. R. C. Martins C. Biasi D. T. Fantoni R. G. Lima \u201cA proposal to monitor muscle contraction through the change of electrical impedance inside a muscle\u201d in 5th IEEE RAS\/EMBS International Conference on Biomedical Robotics and Biomechatronics (IEEE 2014) pp. 763\u2013767.","DOI":"10.1109\/BIOROB.2014.6913870"},{"key":"e_1_3_2_39_2","doi-asserted-by":"publisher","DOI":"10.1088\/0967-3334\/24\/1\/316"},{"key":"e_1_3_2_40_2","doi-asserted-by":"publisher","DOI":"10.1152\/jappl.1999.86.5.1445"},{"key":"e_1_3_2_41_2","doi-asserted-by":"publisher","DOI":"10.1109\/TBME.2022.3188482"},{"key":"e_1_3_2_42_2","doi-asserted-by":"publisher","DOI":"10.1152\/physiol.00023.2019"},{"key":"e_1_3_2_43_2","doi-asserted-by":"publisher","DOI":"10.1093\/icb\/icy054"},{"key":"e_1_3_2_44_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0709212105"},{"key":"e_1_3_2_45_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jbiomech.2021.110800"},{"key":"e_1_3_2_46_2","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6579\/ad10c5"},{"key":"e_1_3_2_47_2","unstructured":"R. H. Miller \u201cHill-based muscle modeling\u201d in Handbook of Human Motion B. M\u00fcller S. I. Wolf G.-P. Brueggemann Z. Deng A. McIntosh F. Miller W. S. Selbie Eds. (Springer 2018); https:\/\/link.springer.com\/referenceworkentry\/10.1007\/978-3-319-30808-1_203-2."},{"key":"e_1_3_2_48_2","doi-asserted-by":"publisher","DOI":"10.3390\/s22051941"},{"key":"e_1_3_2_49_2","doi-asserted-by":"crossref","unstructured":"T. D. Lalitharatne Y. Hayashi K. Teramoto K. Kiguchi \u201cA study on effects of muscle fatigue on EMG-based control for human upper-limb power-assist\u201d in 2012 IEEE 6th International Conference on Information and Automation for Sustainability (IEEE 2012) pp. 124\u2013128.","DOI":"10.1109\/ICIAFS.2012.6419892"},{"key":"e_1_3_2_50_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.clinbiomech.2009.01.010"},{"key":"e_1_3_2_51_2","doi-asserted-by":"publisher","DOI":"10.1002\/mus.27081"},{"key":"e_1_3_2_52_2","doi-asserted-by":"crossref","unstructured":"L. Beckmann A. Cordes E. Saygili A. Schmeink P. Schauerte M. Walter S. Leonhardt \u201cMonitoring of body fluid in patients with chronic heart failure using Bioimpedance\u2013Spectroscopy\u201d in IFMBE Proceedings of the World Congress on Medical Physics and Biomedical Engineering O. D\u00f6ssel W. C. Schlegel Eds. (Springer 2009) pp. 532\u2013535.","DOI":"10.1007\/978-3-642-03885-3_148"},{"key":"e_1_3_2_53_2","doi-asserted-by":"publisher","DOI":"10.1111\/sms.12961"},{"key":"e_1_3_2_54_2","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00720.2021"},{"key":"e_1_3_2_55_2","doi-asserted-by":"crossref","unstructured":"A. Phinyomark E. Campbell E. Scheme \u201cSurface electromyography (EMG) signal processing classification and practical considerations\u201d in Biomedical Signal Processing: Advances in Theory Algorithms and Applications G. Naik Ed. (Springer 2020) pp. 3\u201329; https:\/\/doi.org\/10.1007\/978-981-13-9097-5_1.","DOI":"10.1007\/978-981-13-9097-5_1"},{"key":"e_1_3_2_56_2","doi-asserted-by":"publisher","DOI":"10.1109\/TBME.2020.3027477"},{"key":"e_1_3_2_57_2","doi-asserted-by":"publisher","DOI":"10.1007\/s11154-023-09790-9"},{"key":"e_1_3_2_58_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41746-025-01441-4"}],"container-title":["Science Robotics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.science.org\/doi\/pdf\/10.1126\/scirobotics.aea4580","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T17:58:41Z","timestamp":1790186321000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.science.org\/doi\/10.1126\/scirobotics.aea4580"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,23]]},"references-count":57,"journal-issue":{"issue":"118","published-print":{"date-parts":[[2026,9,23]]}},"alternative-id":["10.1126\/scirobotics.aea4580"],"URL":"https:\/\/doi.org\/10.1126\/scirobotics.aea4580","relation":{},"ISSN":["2470-9476"],"issn-type":[{"value":"2470-9476","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,23]]},"assertion":[{"value":"2025-07-23","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-08-31","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-09-23","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"eaea4580"}}