Your browser doesn't support javascript.
loading
Skeletal muscle fiber type and TMS-induced muscle relaxation in unfatigued and fatigued knee-extensor muscles.
Barbi, Chiara; Temesi, John; Giuriato, Gaia; Laginestra, Fabio Giuseppe; Martignon, Camilla; Moro, Tatiana; Schena, Federico; Venturelli, Massimo; Vernillo, Gianluca.
Afiliación
  • Barbi C; Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
  • Temesi J; Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom.
  • Giuriato G; Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
  • Laginestra FG; Surgical, Medical and Dental Department of Morphological Sciences Related to Transplant, Oncology and Regenerative Medicine, University of Modena and Reggio Emilia, Modena, Italy.
  • Martignon C; Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
  • Moro T; Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
  • Schena F; Department of Biomedical Sciences, University of Padua, Padua, Italy.
  • Venturelli M; Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
  • Vernillo G; Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
Am J Physiol Regul Integr Comp Physiol ; 326(5): R438-R447, 2024 May 01.
Article en En | MEDLINE | ID: mdl-38525536
ABSTRACT
The force drop after transcranial magnetic stimulation (TMS) delivered to the motor cortex during voluntary muscle contractions could inform about muscle relaxation properties. Because of the physiological relation between skeletal muscle fiber-type distribution and size and muscle relaxation, TMS could be a noninvasive index of muscle relaxation in humans. By combining a noninvasive technique to record muscle relaxation in vivo (TMS) with the gold standard technique for muscle tissue sampling (muscle biopsy), we investigated the relation between TMS-induced muscle relaxation in unfatigued and fatigued states, and muscle fiber-type distribution and size. Sixteen participants (7F/9M) volunteered to participate. Maximal knee-extensor voluntary isometric contractions were performed with TMS before and after a 2-min sustained maximal voluntary isometric contraction. Vastus lateralis muscle tissue was obtained separately from the participants' dominant limb. Fiber type I distribution and relative cross-sectional area of fiber type I correlated with TMS-induced muscle relaxation at baseline (r = 0.67, adjusted P = 0.01; r = 0.74, adjusted P = 0.004, respectively) and normalized TMS-induced muscle relaxation as a percentage of baseline (r = 0.50, adjusted P = 0.049; r = 0.56, adjusted P = 0.031, respectively). The variance in the normalized peak relaxation rate at baseline (59.8%, P < 0.001) and in the fatigue resistance (23.0%, P = 0.035) were explained by the relative cross-sectional area of fiber type I to total fiber area. Fiber type I proportional area influences TMS-induced muscle relaxation, suggesting TMS as an alternative method to noninvasively inform about skeletal muscle relaxation properties.NEW & NOTEWORTHY Transcranial magnetic stimulation (TMS)-induced muscle relaxation reflects intrinsic muscle contractile properties by interrupting the drive from the central nervous system during voluntary muscle contractions. We showed that fiber type I proportional area influences the TMS-induced muscle relaxation, suggesting that TMS could be used for the noninvasive estimation of muscle relaxation in unfatigued and fatigued human muscles when the feasibility of more direct method to study relaxation properties (i.e., muscle biopsy) is restricted.
Asunto(s)
Palabras clave

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Músculo Esquelético / Estimulación Magnética Transcraneal Límite: Humans Idioma: En Revista: Am J Physiol Regul Integr Comp Physiol Asunto de la revista: FISIOLOGIA Año: 2024 Tipo del documento: Article País de afiliación: Italia

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Músculo Esquelético / Estimulación Magnética Transcraneal Límite: Humans Idioma: En Revista: Am J Physiol Regul Integr Comp Physiol Asunto de la revista: FISIOLOGIA Año: 2024 Tipo del documento: Article País de afiliación: Italia
...