Motor units in cranial and caudal regions of the upper trapezius muscle have different discharge rates during brief static contractions.
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| Title: | Motor units in cranial and caudal regions of the upper trapezius muscle have different discharge rates during brief static contractions. |
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| Authors: | Falla, D., Farina, D. |
| Source: | Acta Physiologica. Apr2008, Vol. 192 Issue 4, p551-558. 8p. 4 Graphs. |
| Subjects: | Motor unit, Trapezius muscle, Muscle contraction, Motor ability, Muscles |
| Abstract: | Aim: To compare the discharge patterns of motor unit populations from different locations within the upper trapezius muscle during brief submaximal constant-force contractions. Methods: Intramuscular and surface electromyographic (EMG) signals were collected from three sites of the right upper trapezius muscle distributed along the cranial-caudal direction in 11 volunteers during 10 s shoulder abduction at 25% of the maximum voluntary force. Results: A total of 38 motor units were identified at the cranial location, 36 from the middle location and 17 from the caudal location. Initial discharge rate was greatest at the caudal location ( P < 0.05; mean ± SD, cranial: 16.7 ± 3.6 pps, middle: 16.9 ± 4.0 pps, caudal: 19.2 ± 3.3 pps). Discharge rate decreased during the contraction for the most caudal location only ( P < 0.05). Initial estimates of surface EMG root mean square values were highest at the most caudal location ( P < 0.05; cranial: 32.3 ± 20.9 μV, middle: 41.3 ± 21.0 μV, caudal: 51.6 ± 23.6 μV). Conclusion: This study demonstrates non-uniformity of motor unit discharge within the upper trapezius muscle during a brief submaximal constant-force contraction. Location-dependent modulation of discharge rate may reflect spatial dependency in the control of motor units necessary for the development and maintenance of force output. [ABSTRACT FROM AUTHOR] |
| Copyright of Acta Physiologica is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Psychology and Behavioral Sciences Collection |
| FullText | Links: – Type: pdflink Text: Availability: 0 |
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| Header | DbId: pbh DbLabel: Psychology and Behavioral Sciences Collection An: 30100954 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Motor units in cranial and caudal regions of the upper trapezius muscle have different discharge rates during brief static contractions. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Falla%2C+D%2E%22">Falla, D.</searchLink><br /><searchLink fieldCode="AR" term="%22Farina%2C+D%2E%22">Farina, D.</searchLink> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Acta+Physiologica%22">Acta Physiologica</searchLink>. Apr2008, Vol. 192 Issue 4, p551-558. 8p. 4 Graphs. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Motor+unit%22">Motor unit</searchLink><br /><searchLink fieldCode="DE" term="%22Trapezius+muscle%22">Trapezius muscle</searchLink><br /><searchLink fieldCode="DE" term="%22Muscle+contraction%22">Muscle contraction</searchLink><br /><searchLink fieldCode="DE" term="%22Motor+ability%22">Motor ability</searchLink><br /><searchLink fieldCode="DE" term="%22Muscles%22">Muscles</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Aim: To compare the discharge patterns of motor unit populations from different locations within the upper trapezius muscle during brief submaximal constant-force contractions. Methods: Intramuscular and surface electromyographic (EMG) signals were collected from three sites of the right upper trapezius muscle distributed along the cranial-caudal direction in 11 volunteers during 10 s shoulder abduction at 25% of the maximum voluntary force. Results: A total of 38 motor units were identified at the cranial location, 36 from the middle location and 17 from the caudal location. Initial discharge rate was greatest at the caudal location ( P < 0.05; mean ± SD, cranial: 16.7 ± 3.6 pps, middle: 16.9 ± 4.0 pps, caudal: 19.2 ± 3.3 pps). Discharge rate decreased during the contraction for the most caudal location only ( P < 0.05). Initial estimates of surface EMG root mean square values were highest at the most caudal location ( P < 0.05; cranial: 32.3 ± 20.9 μV, middle: 41.3 ± 21.0 μV, caudal: 51.6 ± 23.6 μV). Conclusion: This study demonstrates non-uniformity of motor unit discharge within the upper trapezius muscle during a brief submaximal constant-force contraction. Location-dependent modulation of discharge rate may reflect spatial dependency in the control of motor units necessary for the development and maintenance of force output. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Acta Physiologica is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
| PLink | https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=pbh&AN=30100954 |
| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1111/j.1748-1716.2007.01776.x Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 8 StartPage: 551 Subjects: – SubjectFull: Motor unit Type: general – SubjectFull: Trapezius muscle Type: general – SubjectFull: Muscle contraction Type: general – SubjectFull: Motor ability Type: general – SubjectFull: Muscles Type: general Titles: – TitleFull: Motor units in cranial and caudal regions of the upper trapezius muscle have different discharge rates during brief static contractions. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Falla, D. – PersonEntity: Name: NameFull: Farina, D. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 04 Text: Apr2008 Type: published Y: 2008 Identifiers: – Type: issn-print Value: 17481708 Numbering: – Type: volume Value: 192 – Type: issue Value: 4 Titles: – TitleFull: Acta Physiologica Type: main |
| ResultId | 1 |
