Functional coupling of motor units is modulated during walking in human subjects

D.M. Halliday, B.A. Conway, L.O.D. Christensen, N.L. Hansen, N.P. Peterson, J.B. Neilsen

    Research output: Contribution to journalArticle

    70 Citations (Scopus)

    Abstract

    Time- and frequency-domain analysis of the coupling between pairs of electromyograms (EMG) recorded from leg muscles was investigated during walking in healthy human subjects. For two independent surface EMG signals from the tibialis anterior (TA) muscle, coupling estimated from coherence measurements was observed at frequencies <= 50 Hz, with identifiable peaks occurring in two frequency bands ranging approximately from 8 to 15 and 15 to 20 Hz. The coherence between TA recordings was greatest toward the end of swing, reduced in early swing, and largely absent in midswing. In time-domain estimates constructed from paired TA EMG recordings, a short-lasting central peak indicative of motor-unit synchronization was observed. This feature of motor-unit coupling was also reduced in mid swing. In paired recordings made among triceps surae, quadriceps, and hamstring muscles, a similar pattern of correlation to that for paired TA recordings was observed. However, no significant coupling was observed in recordings for which one EMG recording was made from an ankle flexor/extensor muscle and the other from a knee extensor/flexor muscle. These results demonstrate that for TA a modulation exists in the functional coupling of motor units recruited during swing. The data also indicate that human motoneurons belonging to different muscles are only weakly coupled during walking. This absence of widespread short-term synchronization between the activities of muscles of the leg may provide a basis for the highly adaptive nature of human gait patterns.
    LanguageEnglish
    Pages960-968
    Number of pages8
    JournalJournal of Neurophysiology
    Volume89
    Issue number2
    DOIs
    Publication statusPublished - 2003

    Fingerprint

    Walking
    Electromyography
    Muscles
    Leg
    Quadriceps Muscle
    Motor Neurons
    Gait
    Ankle
    Knee
    Healthy Volunteers

    Keywords

    • neurophysiology
    • biomechanics
    • bioengineering
    • motor neurons
    • walking

    Cite this

    Halliday, D. M., Conway, B. A., Christensen, L. O. D., Hansen, N. L., Peterson, N. P., & Neilsen, J. B. (2003). Functional coupling of motor units is modulated during walking in human subjects. Journal of Neurophysiology, 89(2), 960-968. https://doi.org/10.1152/jn.00844.2002
    Halliday, D.M. ; Conway, B.A. ; Christensen, L.O.D. ; Hansen, N.L. ; Peterson, N.P. ; Neilsen, J.B. / Functional coupling of motor units is modulated during walking in human subjects. In: Journal of Neurophysiology. 2003 ; Vol. 89, No. 2. pp. 960-968.
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    abstract = "Time- and frequency-domain analysis of the coupling between pairs of electromyograms (EMG) recorded from leg muscles was investigated during walking in healthy human subjects. For two independent surface EMG signals from the tibialis anterior (TA) muscle, coupling estimated from coherence measurements was observed at frequencies <= 50 Hz, with identifiable peaks occurring in two frequency bands ranging approximately from 8 to 15 and 15 to 20 Hz. The coherence between TA recordings was greatest toward the end of swing, reduced in early swing, and largely absent in midswing. In time-domain estimates constructed from paired TA EMG recordings, a short-lasting central peak indicative of motor-unit synchronization was observed. This feature of motor-unit coupling was also reduced in mid swing. In paired recordings made among triceps surae, quadriceps, and hamstring muscles, a similar pattern of correlation to that for paired TA recordings was observed. However, no significant coupling was observed in recordings for which one EMG recording was made from an ankle flexor/extensor muscle and the other from a knee extensor/flexor muscle. These results demonstrate that for TA a modulation exists in the functional coupling of motor units recruited during swing. The data also indicate that human motoneurons belonging to different muscles are only weakly coupled during walking. This absence of widespread short-term synchronization between the activities of muscles of the leg may provide a basis for the highly adaptive nature of human gait patterns.",
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    Halliday, DM, Conway, BA, Christensen, LOD, Hansen, NL, Peterson, NP & Neilsen, JB 2003, 'Functional coupling of motor units is modulated during walking in human subjects' Journal of Neurophysiology, vol. 89, no. 2, pp. 960-968. https://doi.org/10.1152/jn.00844.2002

    Functional coupling of motor units is modulated during walking in human subjects. / Halliday, D.M.; Conway, B.A.; Christensen, L.O.D.; Hansen, N.L.; Peterson, N.P.; Neilsen, J.B.

    In: Journal of Neurophysiology, Vol. 89, No. 2, 2003, p. 960-968.

    Research output: Contribution to journalArticle

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    T1 - Functional coupling of motor units is modulated during walking in human subjects

    AU - Halliday, D.M.

    AU - Conway, B.A.

    AU - Christensen, L.O.D.

    AU - Hansen, N.L.

    AU - Peterson, N.P.

    AU - Neilsen, J.B.

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