The technique of macro EMG is used to investigate the motor unit architecture in a number of pathological conditions. Amplitude and area are the most commonly used criteria, but these parameters alone are not sufficient to assess the complexity of the macro MUP morphology. In an attempt to examine the morphology of the macro MUP in more detail, additional measures were investigated including, (...

The spatial and temporal summation of all the single muscle fibers’ electrical activity corresponding to that AHC depolarization is referred to as a motor unit action potential (MUAP/MUP; Fig. 2). In other words, the MUAP is essentially the electrical correlate to the anatomic motor unit. The above noted MUAP’s respective “spatial” and “temporal” qualifiers are related to the fact that: 1) all ...

AbstrartWavelet analysis is a new method for analyzing t h e and frequency contents of signals. We present the Fast Wavelet Transform (FWT) implemented using Rwavelets and non-circular convolutions in the analysis of Motor Unit Action Potentials (MUAPs). This method allows for the fast extraction of localized frequency components of MUAPs that may prove to be valuable in the early and accurate ...

In order to increase insight into the electrical phenomena of active motor units, a computer simulation model has been developed. With this model motor unit action potentials (MUAPs) have been calculated. The model has been based on the superposition of the muscle fibre potentials of the fibres of one motor unit. For verification, calculated MUAPs have been compared with the matching recorded M...

The article presents a proposal to use linear prediction method for a quick analysis of surface myoelectric (EMG) signals. The spectra obtained with the linear prediction (LP) and Fourier methods were compared. The LP method allows for a precise determination of the location and amplitude of the spectrum maximum and observation of changes in muscle tension and contraction phases. EMG spectra of...

The Electromyography (EMG) is a neurophysiological technique for examining the electrical activity of skeletal muscles. The source of electrical signal in EMG is the muscle membrane potential. The muscle fibers innervated by the axonal branches of a motor neuron form a motor unit (MU). The muscle fibers of each motor unit are intermingled with fibers of other MUs [1]. The summation of action po...

The studies were performed on medial gastrocnemius motor units of the rat. Changes in amplitude, duration and latency of motor unit action potentials were monitored in the course of fatigue test in the three types of motor unites: FF (fast twitch, fatigable), FR (fast twitch, resistant), and S (slow twitch, resistant) motor unit. In a majority of the motor units the amplitude of action potentia...

Objective: To evaluate the performance of a recently proposed motor unit action potential (MUAP) averaging method based on a sliding window, and compare it with relevant published methods in normal and pathological muscles. Methods: Three versions of the method (with different window lengths) were compared to three relevant published methods in terms of signal analysis-based merit figures and M...

The electrical signals produced by the muscles and nerves are analyzed to assess the state of neuromuscular function in subjects with suspected neuromuscular disorders. The repetitive activation of several individual motor units (MUs) results in a superposed pulse train and constitutes the electromyogram (EMG) signal. The analysis of the EMG is based on its basic constituent i.e. motor-unit act...

This paper deals with the online decomposition of intramuscular electromyographic (iEMG) signals. A Markov model is proposed, which takes into account a varying number of firing motor neurons. A Bayes filter detects online the firing motor units by using a dictionary of approximated motor unit action potentials waveforms, and estimates precisely the action potential shapes and the respective fi...