000119959 001__ 119959
000119959 005__ 20240319081021.0
000119959 0247_ $$2doi$$a10.1088/1741-2552/ac8c6c
000119959 0248_ $$2sideral$$a130663
000119959 037__ $$aART-2022-130663
000119959 041__ $$aeng
000119959 100__ $$aLubel, Emma
000119959 245__ $$aKinematics of individual muscle units in natural contractions measured in vivo using ultrafast ultrasound
000119959 260__ $$c2022
000119959 5060_ $$aAccess copy available to the general public$$fUnrestricted
000119959 5203_ $$aObjective. The study of human neuromechanical control at the motor unit (MU) level has predominantly focussed on electrical activity and force generation, whilst the link between these, i.e. the muscle deformation, has not been widely studied. To address this gap, we analysed the kinematics of muscle units in natural contractions. Approach. We combined high-density surface electromyography (HDsEMG) and ultrafast ultrasound (US) recordings, at 1000 frames per second, from the tibialis anterior muscle to measure the motion of the muscular tissue caused by individual MU contractions. The MU discharge times were identified online by decomposition of the HDsEMG and provided as biofeedback to 12 subjects who were instructed to keep the MU active at the minimum discharge rate (9.8 ± 4.7 pulses per second; force less than 10% of the maximum). The series of discharge times were used to identify the velocity maps associated with 51 single muscle unit movements with high spatio-temporal precision, by a novel processing method on the concurrently recorded US images. From the individual MU velocity maps, we estimated the region of movement, the duration of the motion, the contraction time, and the excitation–contraction (E–C) coupling delay. Main results. Individual muscle unit motions could be reliably identified from the velocity maps in 10 out of 12 subjects. The duration of the motion, total contraction time, and E–C coupling were 17.9 $ \pm $ 5.3 ms, 56.6 $ \pm $ 8.4 ms, and 3.8 $ \pm $ 3.0 ms (n = 390 across ten participants). The experimental measures also provided the first evidence of muscle unit twisting during voluntary contractions and MU territories with distinct split regions. Significance. The proposed method allows for the study of kinematics of individual MU twitches during natural contractions. The described measurements and characterisations open new avenues for the study of neuromechanics in healthy and pathological conditions.
000119959 536__ $$9info:eu-repo/grantAgreement/EC/H2020/899822/EU/Ultrasound peripheral interface and in-vitro model of human somatosensory system and muscles for motor decoding and restoration of somatic sensations in amputees/SOMA$$9This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 899822-SOMA
000119959 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc-nd$$uhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/
000119959 590__ $$a4.0$$b2022
000119959 592__ $$a1.135$$b2022
000119959 591__ $$aNEUROSCIENCES$$b106 / 272 = 0.39$$c2022$$dQ2$$eT2
000119959 593__ $$aBiomedical Engineering$$c2022$$dQ1
000119959 591__ $$aENGINEERING, BIOMEDICAL$$b42 / 96 = 0.438$$c2022$$dQ2$$eT2
000119959 593__ $$aCellular and Molecular Neuroscience$$c2022$$dQ2
000119959 594__ $$a7.5$$b2022
000119959 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000119959 700__ $$aGrandi Sgambato, Bruno
000119959 700__ $$aBarsakcioglu, Deren Y
000119959 700__ $$0(orcid)0000-0001-8439-151X$$aIbáñez, Jaime
000119959 700__ $$aTang, Meng-Xing
000119959 700__ $$aFarina, Dario
000119959 773__ $$g19, 5 (2022), 056005 [18 pp.]$$pJ. neural eng.$$tJournal of Neural Engineering$$x1741-2560
000119959 8564_ $$s2910894$$uhttps://zaguan.unizar.es/record/119959/files/texto_completo.pdf$$yVersión publicada
000119959 8564_ $$s671158$$uhttps://zaguan.unizar.es/record/119959/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000119959 909CO $$ooai:zaguan.unizar.es:119959$$particulos$$pdriver
000119959 951__ $$a2024-03-18-16:12:46
000119959 980__ $$aARTICLE