Том 50, № 3 (2024)

The paper presents an analysis of changes in postural stability when a person is presented with a video sequence in a virtual reality helmet and from a TV screen. Postural stability was assessed using a computer stabilometer complex. Changes in the stabilometric indicators compared with control tests (before viewing) were shown for both cases (watching videos on the screen and in a virtual reality helmet). Besides, viewing a video sequence in a virtual reality helmet had a greater impact on the instability. While watching a video from a TV screen and in a virtual reality helmet, the contribution of visual information to maintaining balance in the sagittal plane decreased. However, while watching from the TV screen, the contribution of vestibular information for posture control increased. When viewed with virtual reality helmet, the contribution of somatosensory information and the cerebellum increased. The results may suggest that virtual reality requires more conscious corrective mechanisms to stabilize posture.

The paper considers the process of interaction of individual muscles and muscle groups serving various joints of the body in order to stabilize vertical stability disorders caused by respiratory movements of the chest. The most significant control variables in the process of regulation of intermuscular interaction in order to maintain the stability of the vertical position of the body are considered. The analysis was performed using factorization of muscle electrical activity data, values of articular angles and movements of body segments. It was found that the strategy of maintaining a vertical stance is associated with the control of the hip and neck segments, and with an increase in the disturbing effect, other segments of the body are involved in synergy. An increase in the depth of breathing is accompanied by the inclusion of previously unused muscle modules and a change in the degree of involvement of each muscle in the process of regulating the vertical posture. Such inclusion is reflected in the temporal pattern of activation of synergies at the muscular level, which manifests itself in the formation of additional activation peaks in individual phases of the respiratory cycle. In the process of maintaining vertical stability, muscle activity is moderately associated with the regulation of the position of the general center of mass, and is more directed at the formation of kinematic synergies, including changes in the values of a number of articular angles and simultaneous movement of most body segments. The latter, in turn, stabilize variables important for maintaining equilibrium, and synergetic control at the kinematic level increases as the depth of breathing increases.

Proprioception makes an important contribution to the regulation of speed, strength and spatial parameters of movements, determining the level of proficiency in motor skills. However, the effectiveness of various training approaches in relation to voluntary proprioceptive control of target muscles has not been sufficiently studied. In this paper, we investigated the effectiveness of three types of manipulative training: 1) fine coordination, 2) discrete muscle relaxation and 3) their combinations in relation to the accuracy of reproducing: а) the angular deviation of the joystick from the vertical and b) static muscle efforts during the pronation and supination of the joystick. The study involved 40 young (18-35 years old), physically active volunteers who randomly made up 4 groups of 10 people: “Control” (lack of training), “Coordination” (training of passing an analog of a slit maze with a thin probe), “Discrete relaxation” (training of discrete muscle relaxation of pronators and supinators of the forearm), “Combined” (combined training of maze passing and discrete relaxation). Before and after training (n = 10) we evaluated: 1) the accuracy of reproduction of the deviation of the wrist joystick from the vertical by 20, 50, 80 degrees and 2) the accuracy of reproduction of isometric contraction (0, 20, 50 and 80% of the maximum effort) in the descending, ascending directions as well as discrete achievement of any effort level by pronation /supination of the wrist joystick. It was found that coordination training increased the length of the traversed path in 3 minutes with a reduced number of errors, and increased the proprioceptive accuracy of reproducing the angle of deviation of the joystick by 20 degrees also. In the “Discrete Relaxation” group the average modulus of errors in reproducing descending, ascending and discrete forces during supination, as well as the average modulus of errors in reproducing descending, ascending and discrete forces during forearm pronation decreased after course training. At the same time, no changes in the accuracy of reproducing the angular positions of the joystick were found in this group. In the “Combined” group, training led to an increase in the accuracy of reproducing ascending and descending efforts during pronation, as well as the accuracy of descending efforts during supination of the forearm. In addition, in this group, a decrease in the error modulus during reproducing the tilt of the joystick by 50 degrees by supination was revealed. Correlation analysis did not reveal positive links between training changes in proprioceptive control of different modality. Thus, the training effects used on the target muscles of the forearm have a specific effect on the proprioceptive control of muscle effort and spatial position in the hand joints. The high efficiency of discrete relaxation training regarding the accuracy of voluntary efforts allows us to recommend its use in order to increase the level of mastery of the motor skills of the hand.

Post-traumatic stress disorder (PTSD) is an actual medico-social problem. The pathogenesis of PTSD closely relates to impairment of sensorimotor integration (SMI). The effectiveness of psychosomatic disorder therapy for PTSD rehabilitation can be improved by restoring normal sensorimotor integration. The review examines various autonomic, electro-physiological and postural markers of high sensory motor integration in highly skilled athletes and musicians, as well as impairment of these indices in persons with PTSD. We have established that the most accessible and informative indicators of SMI are: an increase in EEG power in the individually adjusted high-frequency alpha-band, a reduction in energy demands for posture control and a decrease in the electromyographic activity of redundant muscles, not involved in motor-cognitive dual task. In the future, it is planned to use these indicators to diagnose stress disorders and to develop sensorimotor integration recovery training in patients with PTSD.

Respiratory sinus arrhythmia (RSA) reflects the functioning of the nervous heart control, predominantly of a parasympathetic nature. The study of RSA mechanisms helps to reveal the physiological patterns of regulation of cardiac activity, and the development of new approaches to its assessment is an urgent medical task. This review will examine experimental approaches that have contributed to the development of modern ideas about autonomic nervous system role in the formation of RSA, as well as the connection between RSA and frequency-matched fluctuations in systemic blood pressure. In addition, we will consider new data on the phase relationships of fluctuations in heart rate and blood pressure in the frequency range of respiratory waves, obtained using wavelet analysis of these physiological signals.

In this review we discuss the effects of exercise on systemic inflammation. The influence of moderate continuous training on humoral immunity and cellular immunity is separately considered. Recent data on the molecular mechanisms of this influence, such as myokines secreted by skeletal muscles and adipokines secreted by adipocytes, are discussed. Clinical data are provided on the effect of moderate physical activity on common diseases — cardiovascular diseases, diabetes, cancer, Alzheimer’s disease and others.

The article considers some psychophysiological mechanisms of the impact of speleoclimate on the human body. The mechanisms of increasing the reserves of the human neuroimmunoendocrine system as a result of a 10-day course of speleotherapy were revealed. Under the influence of speleoclimate, the content of T-lymphocytes, T-helpers, T-cytotoxic lymphocytes increased, an increase in early and late activation of T-lymphocytes and T-regulatory cells, an increase in the number of B-cells and NK cells with the CD3-CD16-CD56+ phenotype; the frequency of occurrence of epithelial cells of the oral cavity with nuclear aberrations decreased. It is noted that the influence of the speleoclimate on the human body is mainly limited by intrasystemic influences, affecting the regulatory system at the level of vagosympathetic interaction. It was revealed that the course of speleotherapy improves the speed of the visual signal, the speed of primary processing of information and the speed of analysis of visual information in terms of the parameters of the sEP. The mechanisms of influence of speleotherapy on the neuroimmunoendocrine system are determined by the initial psychophysiological state of a person. Under the influence of speleotherapy, the vegetative status is restored.