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  • C Orizio
  • 1993
Muscular sound is a mechanical phenomenon detectable at the surface of an active muscle, which has been known and described since 1800. Only recently, because of the availability of reliable transducers and sophisticated analysis techniques, has this signal become attractive for monitoring the mechanical aspects of muscle contraction. The muscular sound(More)
The surface mechanomyogram (MMG) (detectable at the muscle surface as MMG by accelerometers, piezoelectric contact sensors or other transducers) is the summation of the activity of single motor units (MUs). Each MU contribution is related to the pressure waves generated by the active muscle fibres. The first part of this article will review briefly the(More)
The contracting muscle generates a low frequency sound detectable at the belly surface, ranging from 11 to 40 Hz. To study the relationship between the muscular sound and the intensity of the contraction a sound myogram (SMG) was recorded by a contact sensor from the biceps brachii of seven young healthy males performing 4-s isometric contractions from 10%(More)
The contractile properties of muscle are usually investigated by analysing the force signal recorded during electrically elicited contractions. The electrically stimulated muscle shows surface oscillations that can be detected by an accelerometer; the acceleration signal is termed the surface mechanomyogram (MMG). In the study described here we compared, in(More)
The electromyogram (EMG) and intramuscular pressure (IMP) increase linearly with force during voluntary static contractions, while the surface mechanomyogram (MMG) increases linearly only up to approximately 70% of the maximal voluntary contraction (MVC) and then levels off. The aim of this study was to investigate the possible influence of IMP on the(More)
The power spectral analysis of R-R interval variability (RRV) has been estimated by means of an autoregressive method in seven sedentary males at rest, during steady-state cycle exercise at 21 percent maximal oxygen uptake (%VO2max), SEM 2%, 49% VO2max, SEM 2% and 70% VO2max, SEM 2% and during recovery. The RRV, i.e. the absolute power of the spectrum,(More)
The aim of this study was to compare the force (F) and the muscle transverse diameter changes during electrical stimulation of the motor nerve. In four cats the exposed motor nerves of the medial gastrocnemius were stimulated as follows: (a) eight separate trials at fixed firing rates (FR) from 5 to 50 Hz (9 s duration, supramaximal amplitude); (b) 5 to 50(More)
The aim of this work is to define the pattern of summation of the muscle fibre twitches in the surface mechanomyogram (MMG) generation process. For this purpose, two groups of muscle fibres of the extensor digitorum communis (EDC) were stimulated using needle electrodes. To these two artificial (because made by different muscle fibre types) motor units (MU1(More)
The aim of the study was to investigate the influence of two different transcutaneous neuromuscular electrical stimulation procedures on evoked muscle torque and local tissue oxygenation. In the first one (MP mode), the cathode was facing the muscle main motor point and stimulus amplitude was set to the level eliciting the maximal myoelectrical activation(More)
The frequency content of muscular sound (MS), detected by placing a contact sensor transducer over the belly of the biceps brachii during 10 isometric contractions of 4 s each [10-100% of maximal voluntary contraction (MVC)] in seven sedentary men, was analyzed by the maximum entropy spectral estimation and the fast Fourier transform methods. With(More)