The aim of this study was to assess the effects of acute passive stretching on the electrical and mechanical response of a previously fatigued muscle. Eleven participants underwent maximal tetanic stimulations (50 Hz) of the medial gastrocnemius, before and after a fatiguing protocol and after a bout of passive stretching of the fatigued muscle. During contraction, surface electromyography (EMG), mechanomyography (MMG), and force were recorded. The following parameters were calculated: (1) the EMG root mean square (RMS), mean frequency, and fibre conduction velocity; (2) MMGpeak-to-peak and RMS; (3) the peak force, contraction time, half-relaxation time, peak rate of force development (dF/ dt) and its acceleration (d2F/dt2). Fatigue reduced peak force by 18% (P<0.05) and affected the other force, EMG, and MMG parameters. After stretching: (1) all EMG parameters recovered to pre-fatigue values; (2) MMG peak-to-peak remained depressed, while RMS recovered to pre-fatigue values; (3) the peak force, peak rate of force development and its acceleration were further reduced by 22, 18, and 51%, respectively, and half-relaxation time by 40% (P<0.05). In conclusion, acute passive stretching, when applied to a previously fatigued muscle, further depresses the maximum forcegenerating capacity. Although stretching does not alter the electrical parameters of the fatigued muscle, it does affect the mechanical behaviour of the muscle-tendon unit.
Acute passive stretching in a previously-fatigued muscle : electrical and mechanical response during tetanic stimulation / F. Esposito, E. Cè, S. Rampichini, A. Veicsteinas. - In: ACTA PHYSIOLOGICA. - ISSN 1748-1708. - 197:suppl. 672(2009 Sep), pp. 22-22. ((Intervento presentato al 60. convegno Congresso della Società Italiana di Fisiologia tenutosi a Siena nel 2009.
|Titolo:||Acute passive stretching in a previously-fatigued muscle : electrical and mechanical response during tetanic stimulation|
ESPOSITO, FABIO (Primo)
CE', EMILIANO (Secondo)
RAMPICHINI, SUSANNA (Penultimo)
VEICSTEINAS, ARSENIO (Ultimo)
|Parole Chiave:||Electrical stimulation; Electromyography; Mechanomyography; Muscle stiffness|
|Settore Scientifico Disciplinare:||Settore BIO/09 - Fisiologia|
|Data di pubblicazione:||set-2009|
|Enti collegati al convegno:||Società Italiana di Fisiologia|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1080/02640410903165093|
|Appare nelle tipologie:||01 - Articolo su periodico|