Russian Journal of Biomechanics

During the virus CoViD-19 pandemic, people at risk deserve special attention. One of the reasons that risk factors form is a violation of adequate blood circulation. Evaluation of microcirculation resistance by studying the effectiveness of the functional state of resistive vessels is one of the key issues of blood circulation, which plays a very important role at arterial hypertension, diabetes mellitus, Raynaud's phenomenon. In this article, we had discussed the new approaches to the construction of chatbot systems, also we had presented some pilot results about their testing. In situation today, during the period of social restrictions and recommendations on physical distance in the period of the quarantine, people, in need of prevention especially, must have constant control in home. It's very especially important. This can be done with the simplest chatbot systems that are described in the article.

On the basis of investigations of the biomechanical and innervative structure of walking of patients with disseminated sclerosis, authors of this article gave foundation of application of the exoskeleton ExoAtlet in this disease. Earlier, these authors revealed that patients with disseminated sclerosis have some similar disorders, which are characteristic of all patients with diseases of the locomotor system, namely, reduction of walking, velocity, weakening of the support and push functions of the lower extremities, pronounced decrease of maxima of electrical activity of muscles during the locomotor cycle. On the example of the concrete patient, authors established that this patient has the specific peculiarities of walking, characteristic only of this disease. Authors consider that the following peculiarities of walking are specific only to patients with disseminated sclerosis: cyclic character of the vertical component of the ground reaction force Rz and electromiography-pattern of muscles, unsteadiness of gait, triangular or trapezoid shape of the vertical component Rz of the ground reaction force, equinus of the foot and the ankle joint often in combination with recurvation at the knee joint, considerable diminution of the main flexion at the knee joint in one or both lower extremities, reduction of electrical activity of muscles and its prolongation for most part of the stance phase. With the purpose of investigations of the energetic parameters of walking and revealing the resonance properties of the lower extremities in this disease, authors studied electromiography-pattern of two symmetrical muscles of the lower extremities (both mm. rectus femoris and both mm. biceps femoris) during walking at different cadences in this patient. Method of training of walking in the exoskeleton for patient with disseminated sclerosis included the total time of training, time of walking without rest, distance, which patient could walk for the session, walking velocity, cadence and double step length during walking in the exoskeleton, total number of steps for the session. Authors ascertained that considerable improvement of the biomechanical and innervative structure of walking takes place after the course of training in the exoskeleton ExoAtlet in combination with the medicines, changing the course of the disseminated sclerosis, which is revealed in increase of walking velocity, in growth of the amplitude of the angular displacements at the joints of the lower extremities, in disappearance of phenomena of cyclicity of electromiography-pattern, in change of the form of the vertical component Rz of the ground reaction force from the triangular or trapezoid to the clear-cut two-peaked in parallel with increase of the extreme values of Rz curve, in growth of the maximums of activity of all muscles and their concentration in the adequate phase of the locomotor cycle, in rise of the mean electrical activity (muscle capacity) with increase of walking velocity, in appearance of two parabola branches with presence of the distinct minimum in the curve of the summary integral for distance of 10 meters.

The capabilities of the ELATE and MATLAB packages for visualization of the elastic properties of hard tooth tissues are demonstrated. A visual confirmation of the fact of the elastic anisotropy of the hard tissues of the tooth due to the crystal structure of their mineral component was obtained. The study of the indices of anisotropy of enamel and dentin as an inhomogeneous anisotropic medium becomes of practical importance when studying the problems of the strength of tooth tissues and the quality of restorations.

The consequences of injuries and diseases of the shoulder joint can be either isolated or combined with pathology of the cervical spine. The polymorphism of the pathology significantly complicates the task of rehabilitation of such patients. The authors analyzed biomechanical disorders in the shoulder joint in cervical-brachial syndrome with three main types of injuries: articular, vertebrogenic, and mixed myofascial type. It was shown that the greatest difficulty in terms of violation of biomechanics and subsequent rehabilitation is represented by the articular variant, i.e. in patients who have suffered an injury to the capsular ligamentous apparatus of the shoulder joint.

The aim of this work to substantiate the mechanisms of action of low-frequency acoustic vibrations on humans, caused by mechanical interaction of acoustic oscillations with the anatomical structures of the body. One of the modern features of industrial noise is the domination noise spectrum of the low frequency noise and infrasound with high intensity. To characterize these ranges, the scientific literature uses the term low-frequency acoustic oscillations, due to similar physical properties and biological effects on the human body and animals. It is proven that infrasound has negative effects on many organs (respiratory, hearing, vision, etc.) and human systems (central and autonomic nervous, etc.) and leads to the development of diseases, including professional (sensorineural hearing loss, vestibulopathy, autonomic disorders). On this basis, infrasound is included in the list of harmful production factors. A number of biological effects is formed by a direct mechanical interaction of acoustic oscillations with the anatomical structures of the human body. The length of the acoustic wave and its intensity are decisive parameters for the formation of a reaction in the human body. The interaction of low frequency acoustic oscillations with the anatomical structures of the body must be considered as the interaction of two mechanical systems that leads to the development of various physical effects in tissues and organs (diffraction, resonance, elastic waves, cavitation, etc.). The latter are the basis of the direct action of acoustic oscillations and lead to anatomical damage of the tissues, a conformational disturbance of cellular structures and macromolecules, activation of receptors (mechano-, proprio, vestibuloadaptive, etc.). Biomechanical effect of low-frequency acoustic oscillations should be taken into account in the normalization of low frequency sound range, and determining ways and means of protection from low-frequency acoustic oscillations not only the organ of hearing and the head and internal organs.

There is no doubt that the mechanical effect on the so-called bioactive points and areas may be extremely useful and leads sometimes to a complete cure for various ailments. The existence and benefits of a reflex therapy are absolutely indisputable. Indeed, from ancient times to the present, the unique experience and empirical knowledge about the meridians connecting the points of influence and the skin with all body systems have been accumulated in the depths of Eastern medicine. Until now, the physical nature of the meridians is unknown and has not been explained by anyone, that’s why the reflex therapy stands apart from standard medicine and is practiced as a semi-legal occupation, despite its obvious benefits and effectiveness. In this paper, an attempt was made to reveal the physical nature of the meridians and, thereby, legalize this ancient and extremely necessary discipline. The authors propose a coherent hypothesis, the main idea of which is the statement that if there is even a slightest wound, the nervous system will immediately send the impulse to increase the blood supply to this spot, in other words, a special address appears, the fresh blood directs that way and causes the healing. The mechanism of redistribution of blood flow is that there is a certain low-frequency modulation of the heart rate, which leads to a local increase in blood flow, as impact zones are characterized by certain reductions in time with the modulations. The corresponding organ in the body also has a similar address (i.e. a certain frequency), and therefore an intensified blood flow rushes there too, providing a vital effect on this organ. As a result, the supported organ more effectively fights the disease. This, in short, is the mechanism of recovery that nature has in place in the presence of heart rhythm modulations that can be made manageable. Naturally, by saturating the blood with exposure agents, we will obtain an increase in their effectiveness due to local penetration directly into the painful area.