Investigation of Innervation Zone Shift with Continuous Dynamic Muscle Contraction
Autor: | Ken Nishihara; Hisashi Kawai; Yu Chiba; Naohiko Kanemura; Toshiaki Gomi |
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Sprache: | Englisch |
Veröffentlicht: |
2013 |
Quelle: | Directory of Open Access Journals: DOAJ Articles |
Online Zugang: |
http://dx.doi.org/10.1155/2013/174342 https://doaj.org/toc/1748-670X https://doaj.org/toc/1748-6718 1748-670X 1748-6718 doi:10.1155/2013/174342 https://doaj.org/article/4fb72be441af49f1b020fe2a4944d4f7 https://doi.org/10.1155/2013/174342 https://doaj.org/article/4fb72be441af49f1b020fe2a4944d4f7 |
Erfassungsnummer: | ftdoajarticles:oai:doaj.org/article:4fb72be441af49f1b020fe2a4944d4f7 |
Zusammenfassung
Innervation zone (IZ) has been identified as the origin of action potential propagation in isometric contraction. However, IZ shifts with changes in muscle length during muscle activity. The IZ shift has been estimated using raw EMG signals. This study aimed to investigate the movement of IZ location during continuous dynamic muscle contraction, using a computer program. Subjects flexed their elbow joint as repetitive dynamic muscle contractions. EMG signals were recorded from the biceps brachii muscle using an eight-channel surface electrode array. Approximately 100 peaks from EMG signals were detected for each channel and summed to estimate the IZ location. For each subject, the estimated IZ locations were subtracted from the IZ location during isometric contractions with the elbow flexed at 90°. The results showed that the IZ moved significantly with elbow joint movement from 45° to 135°. However, IZ movement was biased with only a 3.9 mm IZ shift on average when the elbow angle was acute but a 16 mm IZ shift on average when it was obtuse. The movement of IZ location during continuous dynamic muscle contraction can be investigated using this signal processing procedure without subjective judgment.