Your browser doesn't support javascript.
loading
Residual force enhancement and force depression in human single muscle fibres.
Pinnell, Rhiannan A M; Mashouri, Parastoo; Mazara, Nicole; Weersink, Erin; Brown, Stephen H M; Power, Geoffrey A.
Afiliación
  • Pinnell RAM; Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada.
  • Mashouri P; Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada.
  • Mazara N; Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada.
  • Weersink E; Health and Performance Centre, Sports Medicine Clinic, University of Guelph, Guelph, Ontario, Canada.
  • Brown SHM; Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada.
  • Power GA; Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada. Electronic address: gapower@uoguelph.ca.
J Biomech ; 91: 164-169, 2019 Jun 25.
Article en En | MEDLINE | ID: mdl-31155213
Residual force depression (rFD) and residual force enhancement (rFE) are intrinsic contractile properties of muscle. rFD is characterized as a decrease in steady-state isometric force following active shortening compared with a purely isometric contraction at the same muscle length and level of activation. By contrast, isometric force is increased following active lengthening compared to a reference isometric contraction at the same muscle length and level of activation; this is termed rFE. To date, there have been no investigations of rFD and rFE in human muscle fibres, therefore the purpose of this study was to determine whether rFD and rFE occur at the single muscle fibre level in humans. rFD and rFE were investigated in maximally activated single muscle fibres biopsied from the vastus lateralis of healthy adults. To induce rFD, fibres were activated and shortened from an average sarcomere length (SL) of 3.2-2.6 µm. Reference isometric contractions were performed at an average SL of 2.6 µm. To induce rFE, fibres were actively lengthened from an average SL of 2.6-3.2 µm and a reference isometric contraction was performed at an average SL of 3.2 µm. Isometric steady-state force was lower following active shortening (p < 0.05), and higher following active lengthening (p < 0.05), as compared to the reference isometric contractions. We demonstrated rFD and rFE in human single fibres which is consistent with previous animal models. The non-responder phenomenon often reported in rFE studies involving voluntary contractions at the whole human level was not observed at the single fibre level.
Asunto(s)
Palabras clave

Texto completo: 1 Bases de datos: MEDLINE Asunto principal: Fibras Musculares Esqueléticas / Fenómenos Mecánicos Tipo de estudio: Prognostic_studies Límite: Adult / Humans / Male Idioma: En Revista: J Biomech Año: 2019 Tipo del documento: Article País de afiliación: Canadá

Texto completo: 1 Bases de datos: MEDLINE Asunto principal: Fibras Musculares Esqueléticas / Fenómenos Mecánicos Tipo de estudio: Prognostic_studies Límite: Adult / Humans / Male Idioma: En Revista: J Biomech Año: 2019 Tipo del documento: Article País de afiliación: Canadá