There is an inherent connection between nervous system and muscle activity during breathing process. Both muscle fiber activation and the propagation of nerve impulses are electrical in its nature, whilst many cognitive functions could be measured by EEG signals. So the logical assumption might be that different breathing patterns, initially spotted by the minute volume changing, could be seen by change in electrophysiology of muscle activity -electromyogram (EMG). This pioneer multidisciplinary investigation has been concentrated on the most passive breathing activity, the prolonged breath holding. The safe and comfort method of physiological breath holding method has been applied. Having in mind number of anatomic and physiological characteristics of human body the two regions for non-invasive EMG measuring had been proposed-the neck and the region of solar plexus. The first test was done by 30 healthy volunteers, the students of sport science. The clear electrophysiology activity in these two regions has been proved. The measured respirational, ECG and two EMG signals has been shown that the sample rate of 200 Hz is quite enough. This opens the new possibilities for further experiments to be performed by enlarged number of electropoligraphical signals simultaneously taken. Whilst approaching to the point of physiological answer of the breath holding, the concerning increase of both average power and power spectral density had been spotted, especially in the regions of delta and theta.

Introduction/Objective. Numerous studies on surface electromyographic (sEMG) signals in response to different respiratory parameters, particularly on sternocleidomastoid (SCM) muscles and diaphragm (DIA), indicated the promising advantages of their simultaneous monitoring with possible applications in the analysis of their correlation. This motivated ? detailed statistical analysis of the average power (PAV) on sEMG signals during prolonged breath-holding, simultaneously measured in the SCM and DIA areas. Methods. The physiological breath-holding method was applied to 30 healthy volunteers, with sEMG of SCM and DIA regions measured before, during, and after the breath-holding exercise. All the subjects were sitting in an upward position, with nostrils closed by the right index finger and thumb during breath-hold. To synchronize the records, the user would press a special switch using the other hand at the beginning and at the end of breath-holding experiment. The average power of sEMG (PAV) was measured for each 500 ms signal window. Results. The PAV remains constant before and 3 seconds after the exercise. During the ending of breathholding, at least one region had the PAV afflux of a minimum of 91%. Student?s t-test between SCM signals shows a significant difference of p < 0.001, while the DIA lacks it. Although the results showed that SCM is the dominant region in 76.67% of cases, the exclusive PAV afflux in the DIA region was detected in precisely five cases (16.67% of the total namber of participants). Conclusions. Our research concludes that there is the necessity of simultaneous measurement of SCM and DIA to observe dominant changes in sEMG during breath-holding. The physiological response of the respiratory center can be observed by approximately doubling PAV in one of SCM or DIA regions.

The subject of this research is the individual respiration constant calculated based on the respiratory musculature breathing equation. This non-experimental observation conducted on a sample of students from the Faculty of Sports and Physical Education in Belgrade (N=30). The measurement aimed at the acquisition and analysis of the average power of the surface electromyography signal (sEMG) in the protocols before and after prolonged respiratory retention. The results of the research showed that the individual coefficient of control break (Cp) represents a unique characteristic of the respiratory muscles of the subjects. In a relatively trained sample of young people of both sexes, it determined that after holding their breath, until the moment of the so-called "stroke" (progression of respiration to adapt to a stressful situation), recovery time has a linear course and is directly related to the engagement of the monitored respiratory muscles of the subjects, i.e., indirectly the capacity of the individual to assimilate O2 from the inhaled air. In the practical meaning of this research, we emphasize that individual results can be correlated with the equation of respiration of respiratory muscles, to find out and approach the original method for the presented personal respirational constant.