sEMG Wavelet-based Indices predicts Muscle Power Loss during Dynamic Contractions

• Autores: Miriam González Izal, Ignacio Rodríguez Carreño , Armando Malanda Trigueros , Fermín Mallor Giménez , Ion Navarro Amezqueta, Esteban Gorostiaga Ayestarán, Mikel Izquierdo
• Localización: Working Papers ( Universidad de Navarra. Facultad de Ciencias Económicas y Empresariales ), Nº. 17, 2009
• Idioma: inglés
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  • Purpose: To compare the sensitivity to estimate acute exercise-induced changes on muscle power output during a dynamic fatiguing protocol from new surface electromyography (sEMG) indices based on the discrete wavelet transform, as well as from amplitude and spectral indices of muscle fatigue (i.e. mean average voltage, median frequency and ratios between spectral moments). Methods: 15 trained subjects performed 5 sets consisting of 10 leg press, with 2 minutes rest between sets. sEMG was recorded from vastus medialis (VM) muscle. Several surface electromyographic parameters were computed. These were: mean average voltage (MAV), median spectral frequency (Fmed), Dimitrov spectral index of muscle fatigue (FInsm5), as well as other five parameters obtained from the discrete wavelet transform (DWT) as ratios between different scales. Results: The new wavelet indices as a single parameter predictor accounted for 46.6% of the performance variance of changes in muscle power and the log FInsm5 and MAV as a two factor combination predictor accounted for 49.8%. On the other hand, they showed the highest robustness in presence of additive white Gaussian noise for different signal to noise ratios (SNRs). Conclusions: The sEMG wavelet indices proposed may be a useful tool to map changes in muscle power output during dynamic high-loading fatiguing task.