A Method for Identification of Mechanical Response of Motor Units in Skeletal Muscle Voluntary Contractions Using Ultrafast Ultrasound Imaging—Simulations and Experimental Tests
The central nervous system coordinates movement through forces generated by motor units (MUs) in skeletal muscles. To analyze MUs function is essential in sports, rehabilitation medicine applications, and neuromuscular diagnostics. The MUs and their function are studied using electromyography. Typic...
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| Format: | Article |
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IEEE
2020-01-01
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| Series: | IEEE Access |
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| Online Access: | https://ieeexplore.ieee.org/document/9032320/ |
| _version_ | 1811274156477513728 |
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| author | Robin Rohlen Erik Stalberg Karen-Helene Stoverud Jun Yu Christer Gronlund |
| author_facet | Robin Rohlen Erik Stalberg Karen-Helene Stoverud Jun Yu Christer Gronlund |
| author_sort | Robin Rohlen |
| collection | DOAJ |
| description | The central nervous system coordinates movement through forces generated by motor units (MUs) in skeletal muscles. To analyze MUs function is essential in sports, rehabilitation medicine applications, and neuromuscular diagnostics. The MUs and their function are studied using electromyography. Typically, these methods study only a small muscle volume (1 mm<sup>3</sup>) or only a superficial (<1 cm) volume of the muscle. Here we introduce a method to identify so-called mechanical units, i.e., the mechanical response of electrically active MUs, in the whole muscle (<inline-formula> <tex-math notation="LaTeX">$4\times 4$ </tex-math></inline-formula> cm, cross-sectional) under voluntary contractions by ultrafast ultrasound imaging and spatiotemporal decomposition. We evaluate the performance of the method by simulation of active MUs’ mechanical response under weak contractions. We further test the experimental feasibility on eight healthy subjects. We show the existence of mechanical units that contribute to the tissue dynamics in the biceps brachii at low force levels and that these units are similar to MUs described by electromyography with respect to the number of units, territory sizes, and firing rates. This study introduces a new potential neuromuscular functional imaging method, which could be used to study a variety of questions on muscle physiology that previously were difficult or not possible to address. |
| first_indexed | 2024-04-12T23:12:38Z |
| format | Article |
| id | doaj.art-60debf6b0e8844e8a2e90721f08346c7 |
| institution | Directory Open Access Journal |
| issn | 2169-3536 |
| language | English |
| last_indexed | 2024-04-12T23:12:38Z |
| publishDate | 2020-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Access |
| spelling | doaj.art-60debf6b0e8844e8a2e90721f08346c72022-12-22T03:12:45ZengIEEEIEEE Access2169-35362020-01-018502995031110.1109/ACCESS.2020.29800539032320A Method for Identification of Mechanical Response of Motor Units in Skeletal Muscle Voluntary Contractions Using Ultrafast Ultrasound Imaging—Simulations and Experimental TestsRobin Rohlen0https://orcid.org/0000-0003-4328-5467Erik Stalberg1https://orcid.org/0000-0003-0249-3921Karen-Helene Stoverud2https://orcid.org/0000-0002-3423-2083Jun Yu3https://orcid.org/0000-0001-5673-620XChrister Gronlund4https://orcid.org/0000-0003-4288-1208Department of Radiation Sciences, Biomedical Engineering, Umeå University, Umeå, Sweden2Department of Clinical Neurophysiology, Department of Neurosciences, University Hospital, Uppsala, SwedenDepartment of Radiation Sciences, Biomedical Engineering, Umeå University, Umeå, SwedenDepartment of Mathematics and Mathematical Statistics, Umeå University, Umeå, SwedenDepartment of Radiation Sciences, Biomedical Engineering, Umeå University, Umeå, SwedenThe central nervous system coordinates movement through forces generated by motor units (MUs) in skeletal muscles. To analyze MUs function is essential in sports, rehabilitation medicine applications, and neuromuscular diagnostics. The MUs and their function are studied using electromyography. Typically, these methods study only a small muscle volume (1 mm<sup>3</sup>) or only a superficial (<1 cm) volume of the muscle. Here we introduce a method to identify so-called mechanical units, i.e., the mechanical response of electrically active MUs, in the whole muscle (<inline-formula> <tex-math notation="LaTeX">$4\times 4$ </tex-math></inline-formula> cm, cross-sectional) under voluntary contractions by ultrafast ultrasound imaging and spatiotemporal decomposition. We evaluate the performance of the method by simulation of active MUs’ mechanical response under weak contractions. We further test the experimental feasibility on eight healthy subjects. We show the existence of mechanical units that contribute to the tissue dynamics in the biceps brachii at low force levels and that these units are similar to MUs described by electromyography with respect to the number of units, territory sizes, and firing rates. This study introduces a new potential neuromuscular functional imaging method, which could be used to study a variety of questions on muscle physiology that previously were difficult or not possible to address.https://ieeexplore.ieee.org/document/9032320/Biomedical engineeringblind source separationphysiologyultrasonic imaging |
| spellingShingle | Robin Rohlen Erik Stalberg Karen-Helene Stoverud Jun Yu Christer Gronlund A Method for Identification of Mechanical Response of Motor Units in Skeletal Muscle Voluntary Contractions Using Ultrafast Ultrasound Imaging—Simulations and Experimental Tests IEEE Access Biomedical engineering blind source separation physiology ultrasonic imaging |
| title | A Method for Identification of Mechanical Response of Motor Units in Skeletal Muscle Voluntary Contractions Using Ultrafast Ultrasound Imaging—Simulations and Experimental Tests |
| title_full | A Method for Identification of Mechanical Response of Motor Units in Skeletal Muscle Voluntary Contractions Using Ultrafast Ultrasound Imaging—Simulations and Experimental Tests |
| title_fullStr | A Method for Identification of Mechanical Response of Motor Units in Skeletal Muscle Voluntary Contractions Using Ultrafast Ultrasound Imaging—Simulations and Experimental Tests |
| title_full_unstemmed | A Method for Identification of Mechanical Response of Motor Units in Skeletal Muscle Voluntary Contractions Using Ultrafast Ultrasound Imaging—Simulations and Experimental Tests |
| title_short | A Method for Identification of Mechanical Response of Motor Units in Skeletal Muscle Voluntary Contractions Using Ultrafast Ultrasound Imaging—Simulations and Experimental Tests |
| title_sort | method for identification of mechanical response of motor units in skeletal muscle voluntary contractions using ultrafast ultrasound imaging x2014 simulations and experimental tests |
| topic | Biomedical engineering blind source separation physiology ultrasonic imaging |
| url | https://ieeexplore.ieee.org/document/9032320/ |
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