Velikie Luki State Academy of Physical Culture and Sports

The dielectric properties of nanocomposite materials obtained by dispersing Rochelle salt in porous dielectric matrices of zeolites, asbestos, and opals are studied. A nonmonotonic dependence of the Curie temperature on the size of ferroelectric nanoparticles is established.

The study aims to examine the specific psychological characteristics of the functioning of male and female student basketball teams. The purpose of the study is to identify and analyze the distinctive features and interrelationships of the relationships within the "coach-athlete" system and the characteristics of the psychological climate in basketball teams of different genders competing in the ASB of Russia. Research methods and organization. The study was conducted with the participation of basketball teams of girls and boys competing in the 'Center' division of the Russian Basketball Federation (ASB) for the 2024-2025 season. To achieve the set objectives, specialized methodologies for psychological diagnostics of relationships within the 'coach-athlete' system and the psychological climate of the teams were applied. Correlation analysis using Spearman's method was employed to establish connections. Research results and conclusions. It has been established that the evaluations of relationship components within the "coach-athlete" system among young male basketball players are higher compared to those of female basketball players. Significant differences have been identified in the perception of the psychological atmosphere between male and female basketball teams, with female basketball players' evaluations significantly more frequently falling into the discomfort zone. The correlation between relationships in the "coach-athlete" system and the psychological climate was found exclusively in girls' teams with a female coach. No such correlations were detected in men's basketball teams.

The features of the spatial-temporal structuring of intermuscular interaction during locomotion in conditions of full and partial unloading of body weight were studied. The extraction of muscle synergies was performed using the principal component analysis. It is established that the stability of muscle modules and stereotypical patterns of their temporary activation with varying degrees of afferentation are due to the implementation of motor synergy programs. It was revealed that only the presence, but not the power of the afferent flow from the receptor complex of the lower extremities makes a significant contribution to the formation of inter-extremity synergetic patterns and regulation of the degree of involvement of muscles in synergy. The formation of various time profiles in the structure of synergies is due to the redundancy of the organization of control structures, thanks to which reliable management of physiological functions is carried out. The implementation of synergy programs weakly depends on the magnitude and nature of proprioceptive and supportive afferentation. Only the presence, but not the power, of the afferent flow from the receptor complex of the lower extremities makes a significant contribution to the formation of interfacial synergetic patterns and the regulation of the degree of muscle involvement in synergy.

The article describes the results of studies on the impulse activity of various groups of afferent fibers and EMG patterns of lower leg antagonist muscles when walking without, during, and after transcutaneous electrical stimulation of the dorsal roots of the lower thoracic spinal cord of a person. Using a mathematical model based on the prediction of the triggering of muscle spindles, variability in the manifestation of impulse activity of various afferents of the tibialis anterior (TA) and gastrocnemius medialis (GM) muscle when walking under different experimental conditions is shown. It was found that walking on a movable treadmill tape in the absence of spinal cord stimulation was accompanied by strong impulse activity of afferents of I (Ia and Ib) and II groups of GM and increased excitability of its motorneuron pool and weakening of afferent activity and excitability of TA. On the contrary, electrical stimulation of the spinal cord during walking caused strong impulsive activity of group II of TA afferents and moderate in GM, while the activity of Ia fibers in TA and GM decreased to moderate impulsivity, Ib afferents of the same muscles had the weakest activity, and the excitability of the GM motor neuron pool was greater than TA. During the postactivation period, walking was accompanied by increased impulses of afferent fibers of group Ib and II of GM, weakening of afferent flows of Ib of TA and Ia afferents of GM, but along with this, afferent signals of group Ia and II to the motor neuron nucleus of TA decreased to moderate impulses, and excitability of the motor neuron pool of GM was higher than TA. The supposed reflex mechanisms of locomotion regulation are discussed on the basis of well-known phenomena associated with the interaction of various afferent inputs to the spinal cord neuronal apparatus in the system of lower leg antagonist muscles.

Описаны результаты исследований по изучению импульсной активности различных групп афферентных волокон и ЭМГ-паттернов мышц-антагонистов голени при ходьбе без, вовремя и после чрескожной электрической стимуляции дорсальных корешков нижнегрудного отдела спинного мозга человека. С помощью применения математической модели, основанной на прогнозировании срабатывания мышечных веретен, показана ва риабельность в проявлении импульсной активности различных афферентов m. tibiallis anterior и m. gastrocnemius med. при ходьбе в разных экспериментальных условиях.
 
 Ключевые слова: чрескожная электрическая стимуляция спинного мозга (ЧЭССМ), афференты, интернейроны, спинальное торможение, мышцы, локомоторные движения.

Background: A growing number of studies have reported Coronavirus disease (COVID-19)-related to both respiratory and central nervous system dysfunctions. This study evaluates the neuromodulatory effects of spinal cord transcutaneous stimulation (scTS) on the respiratory functional state in healthy controls and patients with post-COVID-19 respiratory deficits as a step toward the development of a rehabilitation strategy for these patients.; Methods: In this before-after, interventional, case-controlled clinical study, ten individuals with post-acute COVID-19 respiratory deficits and eight healthy controls received a single twenty-minute-long session of modulated monophasic scTS delivered over the T5 and T10 spinal cord segments. Forced Vital Capacity (FVC), Peak Forced Inspiratory Flow (PIF), Peak Expiratory Flow (PEF), Time-To-Peak of Inspiratory Flow (tPIF), and Time-To-Peak of Expiratory Flow (tPEF) were assessed before and after the intervention; Results: In COVID-19 group, the scTS intervention led to significantly increased PIF (p= .040) and PEF (p= .049) in association with significantly decreased tPIF (p= .035) and tPEF (p= .013). In the Control Group, the exposure to scTS also resulted in significantly increased PIF (p= .010) and significantly decreased tPIF (p= .031). Unlike the results in COVID-19 group, there was significantly decreased PEF (p= .028) in association with significantly increased tPEF (p= .036). There were no changes for FVC after scTS in both groups (p= .67 and p= .503); Conclusions: In post-COVID-19 patients scTS facilitates excitation of both inspiratory and expiratory spinal neural networks leading to an immediate improvement of respiratory functional performance. This neuromodulation approach could be utilized in rehabilitation programs for patients with COVID-19 respiratory deficits.

The physical and neuropsychiatric overstrain of the personnel of the team participating in the “Аirborne platoon” competition is caused by the influence of harmful factors of military service, the volume of training activities and entails a decrease in the functional state, which can cause injury to the participants of the competition. This will lead to disruption of the sports training of the entire team and to poor-quality performance of military personnel at the international stage of the competition. And a timely assessment of the functional state with the help of modern hardware and software systems for the analysis of heart rate variability will help in assessing the functional state and regulating the process of preparing the national team. The purpose of the study was to assess the functional state of military personnel, participants in the field training competition “Landing Platoon”, in the pre-competition period with the help of modern hardware and software systems and to develop proposals for regulating the process of training soldiers-athletes. In the course of the study, it was found that modern hardware and software systems for assessing the functional state, based on the analysis of heart rate variability, can help in constant dynamic monitoring of the reactivity of regulatory systems that determine the effectiveness of adaptive mechanisms, and on the basis of the results obtained, make adjustments to sports training plans. Физическое и нервно психическое перенапряжение личного состава команды, участницы конкурса «Десантный взвод», вызвано воздействием вредных факторов военной службы, объемами тренировочных мероприятий и влечет за собой понижение функционального состояния, которое может вызвать травмирование участников состязаний. Это приведет к срыву спортивной подготовки всей команды и к некачественному выступлению военнослужащих на международном этапе конкурса. А своевременная оценка функционального состояния с помощью современных аппаратно-программных комплексов по анализу вариабельности сердечного ритма поможет в оценке функционального состояния и регулировании процесса подготовки сборной команды. Целью исследования была оценка функционального состояния военнослужащих, участников конкурса по полевой выучке «Десантный взвод», в предсоревновательный период с помощью современных аппаратно-программных комплексов и разработка предложений по регулированию процесса подготовки воинов-спортсменов. В ходе исследования было установлено, что современные аппаратно-программные комплексы по оценке функционального состояния, на основе анализа вариабельности сердечного ритма, могут помочь в постоянном динамическом контроле за реактивностью регуляторных систем, определяющих эффективность работы адаптационных механизмов, и на основе полученных результатов, вносить корректировку в планы спортивной подготовки.

The aim of the work was to study the cortical-spinal excitability and conducting ability of the motor system using muscle potentials caused by magnetic stimulation of the motor cortex of the brain and spinal segments at the level of the C6–C7 and T12–L1 vertebrae in athletes of different specializations, and to correlate these parameters with psychophysiological characteristics. The researches revealed: 1) the stayers had the highest level of excitability of cortical neurons and motor neurons of the cervical and lumbar thickenings of the spinal cord, controlling the activity of shoulder, forearm, hip and shin muscles; the sprinters had the lowest level, while that of the basketball players’ was in between; 2) the sprinters and the basketball players displayed the highest conductive capacity of the corticospinal tract (CST), the stayers had the lowest one; 3) sprinters and basketball players had a higher rate of simple and complex sensorimotor reactions as an indicator of neuromotor (lability and mobility of the nervous system) and cognitive processes than stayers; 4) basketball players had the highest accuracy of complex sensorimotor reactions and the ability to anticipate the course of events as a sign of cognitive success than other athletes; 5) cortical-spinal excitability positively correlated with the accuracy of movements (in basketball players) and negatively with the conductive ability of the CST and the speed of simple and complex sensorimotor reactions (in sprinters and stayers). Athletes who train speed, endurance and coordination of movement have distinctive features and the relationship between the functional state of the CST and motor-cognitive reactions.

The study considers the synergetic effects manifested at the level of interaction between the various parts of the musculoskeletal system with the patterns of bioelectrical activity of skeletal muscles within the framework of the concept of hierarchical, modular principle of control. Motor synergies were studied at the muscular, kinematic, and neuronal levels. The spatial and temporal structure of motor synergies during the performance of a short straight punch by highly skilled boxers was considered. Synergies were extracted using factor analysis by principal component extraction. It was found that the muscles that form the spatial structure of the first synergy have patterns of impulse activity of the control signals characteristic of the synergy. The spatial-temporal characteristics of the movements of the body segments, as well as the parameters of the electrical activity of the skeletal muscles in the structure of synergies, demonstrate high stability in repeated realizations of the motor action and low variability in the intra- and interindividual comparison. The intermuscular interaction characteristic of synergy can be achieved by different strategies for organizing the impulse activity of motor units. A movement that is complex in coordination can have different temporal patterns of synergy activation, but the patterns of one form can be shifted in time relative to each other when they are compared during multiple realizations of a model movement.

В статье исследуется значение массового и профессионального спортивного ориентирования в росте благосостояния общества и повышении качества жизни населения. Рассматривается влияние спортивного ориентирования на производительность труда, физическая активность населения, продолжительность жизни, повышение качества жизни (в том числе, людей с ограниченными возможностями здоровья). Выявлена роль спортивного ориентирования в восстановлении трудового, интеллектуального, физического и эмоционального потенциала населения, обогащении досуга.