Task-dependent activity of motor unit populations in feline ankle extensor muscles

E.F. Hodson-Tole, A. Pantall, H. Maas, B.J. Farrell, R.J. Gregor, B.I. Prilutsky

    Research output: Contribution to JournalArticleAcademicpeer-review

    Abstract

    Understanding the functional significance of the morphological diversity of mammalian skeletal muscles is limited by technical difficulties of estimating the contribution of motor units with different properties to unconstrained motor behaviours. Recently developed wavelet and principal components analysis of intramuscular myoelectric signals has linked signals with lower and higher frequency contents to the use of slower and faster motor unit populations. In this study we estimated the relative contributions of lower and higher frequency signals of cat ankle extensors (soleus, medial and lateral gastrocnemii, plantaris) during level, downslope and upslope walking and the paw-shake response. This was done using the first two myoelectric signal principal components (PCI, PCII), explaining over 90% of the signal, and an angle, a function of PCI/PCII, indicating the relative contribution of slower and faster motor unit populations. Mean myoelectric frequencies in all walking conditions were lowest for slow soleus (234 Hz) and highest for fast gastrocnemii (307 and 330 Hz) muscles. Motor unit populations within and across the studied muscles that demonstrated lower myoelectric frequency (suggesting slower populations) were recruited during tasks and movement phases with lower mechanical demands on the ankle extensors - during downslope and level walking and in early walking stance and paw-shake phases. With increasing mechanical demands (upslope walking, mid-phase of paw-shake cycles), motor unit populations generating higher frequency signals (suggesting faster populations) contributed progressively more. We conclude that the myoelectric frequency contents within and between feline ankle extensors vary across studied motor behaviours, with patterns that are generally consistent with muscle fibre-type composition. © 2012. Published by The Company of Biologists Ltd.
    Original languageEnglish
    Pages (from-to)3711-3722
    Number of pages12
    JournalJournal of Experimental Biology
    Volume215
    DOIs
    Publication statusPublished - 2012

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    Felidae
    Ankle
    walking
    Motor Activity
    muscle
    Walking
    cats
    Muscles
    muscles
    Population
    Principal Component Analysis
    wavelet
    principal component analysis
    muscle fibers
    Skeletal Muscle
    Cats
    biologists
    skeletal muscle

    Cite this

    Hodson-Tole, E. F., Pantall, A., Maas, H., Farrell, B. J., Gregor, R. J., & Prilutsky, B. I. (2012). Task-dependent activity of motor unit populations in feline ankle extensor muscles. Journal of Experimental Biology, 215, 3711-3722. https://doi.org/10.1242/jeb.068601
    Hodson-Tole, E.F. ; Pantall, A. ; Maas, H. ; Farrell, B.J. ; Gregor, R.J. ; Prilutsky, B.I. / Task-dependent activity of motor unit populations in feline ankle extensor muscles. In: Journal of Experimental Biology. 2012 ; Vol. 215. pp. 3711-3722.
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    abstract = "Understanding the functional significance of the morphological diversity of mammalian skeletal muscles is limited by technical difficulties of estimating the contribution of motor units with different properties to unconstrained motor behaviours. Recently developed wavelet and principal components analysis of intramuscular myoelectric signals has linked signals with lower and higher frequency contents to the use of slower and faster motor unit populations. In this study we estimated the relative contributions of lower and higher frequency signals of cat ankle extensors (soleus, medial and lateral gastrocnemii, plantaris) during level, downslope and upslope walking and the paw-shake response. This was done using the first two myoelectric signal principal components (PCI, PCII), explaining over 90{\%} of the signal, and an angle, a function of PCI/PCII, indicating the relative contribution of slower and faster motor unit populations. Mean myoelectric frequencies in all walking conditions were lowest for slow soleus (234 Hz) and highest for fast gastrocnemii (307 and 330 Hz) muscles. Motor unit populations within and across the studied muscles that demonstrated lower myoelectric frequency (suggesting slower populations) were recruited during tasks and movement phases with lower mechanical demands on the ankle extensors - during downslope and level walking and in early walking stance and paw-shake phases. With increasing mechanical demands (upslope walking, mid-phase of paw-shake cycles), motor unit populations generating higher frequency signals (suggesting faster populations) contributed progressively more. We conclude that the myoelectric frequency contents within and between feline ankle extensors vary across studied motor behaviours, with patterns that are generally consistent with muscle fibre-type composition. {\circledC} 2012. Published by The Company of Biologists Ltd.",
    author = "E.F. Hodson-Tole and A. Pantall and H. Maas and B.J. Farrell and R.J. Gregor and B.I. Prilutsky",
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    doi = "10.1242/jeb.068601",
    language = "English",
    volume = "215",
    pages = "3711--3722",
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    Hodson-Tole, EF, Pantall, A, Maas, H, Farrell, BJ, Gregor, RJ & Prilutsky, BI 2012, 'Task-dependent activity of motor unit populations in feline ankle extensor muscles' Journal of Experimental Biology, vol. 215, pp. 3711-3722. https://doi.org/10.1242/jeb.068601

    Task-dependent activity of motor unit populations in feline ankle extensor muscles. / Hodson-Tole, E.F.; Pantall, A.; Maas, H.; Farrell, B.J.; Gregor, R.J.; Prilutsky, B.I.

    In: Journal of Experimental Biology, Vol. 215, 2012, p. 3711-3722.

    Research output: Contribution to JournalArticleAcademicpeer-review

    TY - JOUR

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    AU - Hodson-Tole, E.F.

    AU - Pantall, A.

    AU - Maas, H.

    AU - Farrell, B.J.

    AU - Gregor, R.J.

    AU - Prilutsky, B.I.

    PY - 2012

    Y1 - 2012

    N2 - Understanding the functional significance of the morphological diversity of mammalian skeletal muscles is limited by technical difficulties of estimating the contribution of motor units with different properties to unconstrained motor behaviours. Recently developed wavelet and principal components analysis of intramuscular myoelectric signals has linked signals with lower and higher frequency contents to the use of slower and faster motor unit populations. In this study we estimated the relative contributions of lower and higher frequency signals of cat ankle extensors (soleus, medial and lateral gastrocnemii, plantaris) during level, downslope and upslope walking and the paw-shake response. This was done using the first two myoelectric signal principal components (PCI, PCII), explaining over 90% of the signal, and an angle, a function of PCI/PCII, indicating the relative contribution of slower and faster motor unit populations. Mean myoelectric frequencies in all walking conditions were lowest for slow soleus (234 Hz) and highest for fast gastrocnemii (307 and 330 Hz) muscles. Motor unit populations within and across the studied muscles that demonstrated lower myoelectric frequency (suggesting slower populations) were recruited during tasks and movement phases with lower mechanical demands on the ankle extensors - during downslope and level walking and in early walking stance and paw-shake phases. With increasing mechanical demands (upslope walking, mid-phase of paw-shake cycles), motor unit populations generating higher frequency signals (suggesting faster populations) contributed progressively more. We conclude that the myoelectric frequency contents within and between feline ankle extensors vary across studied motor behaviours, with patterns that are generally consistent with muscle fibre-type composition. © 2012. Published by The Company of Biologists Ltd.

    AB - Understanding the functional significance of the morphological diversity of mammalian skeletal muscles is limited by technical difficulties of estimating the contribution of motor units with different properties to unconstrained motor behaviours. Recently developed wavelet and principal components analysis of intramuscular myoelectric signals has linked signals with lower and higher frequency contents to the use of slower and faster motor unit populations. In this study we estimated the relative contributions of lower and higher frequency signals of cat ankle extensors (soleus, medial and lateral gastrocnemii, plantaris) during level, downslope and upslope walking and the paw-shake response. This was done using the first two myoelectric signal principal components (PCI, PCII), explaining over 90% of the signal, and an angle, a function of PCI/PCII, indicating the relative contribution of slower and faster motor unit populations. Mean myoelectric frequencies in all walking conditions were lowest for slow soleus (234 Hz) and highest for fast gastrocnemii (307 and 330 Hz) muscles. Motor unit populations within and across the studied muscles that demonstrated lower myoelectric frequency (suggesting slower populations) were recruited during tasks and movement phases with lower mechanical demands on the ankle extensors - during downslope and level walking and in early walking stance and paw-shake phases. With increasing mechanical demands (upslope walking, mid-phase of paw-shake cycles), motor unit populations generating higher frequency signals (suggesting faster populations) contributed progressively more. We conclude that the myoelectric frequency contents within and between feline ankle extensors vary across studied motor behaviours, with patterns that are generally consistent with muscle fibre-type composition. © 2012. Published by The Company of Biologists Ltd.

    U2 - 10.1242/jeb.068601

    DO - 10.1242/jeb.068601

    M3 - Article

    VL - 215

    SP - 3711

    EP - 3722

    JO - Journal of Experimental Biology

    JF - Journal of Experimental Biology

    SN - 0022-0949

    ER -