Postural control is a multilevel adaptive system that stabilizes the body in space through dynamic sensory rebalancing and predictive neuromotor regulation. This review synthesizes current data on the neural mechanisms of balance maintenance, individual strategies for integrating multisensory information, and the role of immersive virtual reality as a controlled experimental and neuromodulation platform, synthesising evidence from 73 studies across neuroscience, cognitive psychology, and VR-based rehabilitation. Particular attention is paid to the cognitive style of “field dependence/independence”, which reflects stable preferences for the dominance of visual or vestibular-proprioceptive signals and consistently predicts the selection of postural strategies. We show that traditional averaged models ignore interpersonal variability, whereas immersive VR allows for the parametric induction of sensory conflicts, quantitative assessment of sensory dependence profiles, and facilitates the study of adaptive reorganization at the cortical, brainstem, and spinal levels. The review substantiates the need to move from standardized protocols to personalized approaches in diagnostics and neurorehabilitation that consider individual patterns of input rebalancing. The integration of behavioural metrics with neurophysiological markers in a VR environment provides a foundation for developing predictive balance models and targeted training interventions. However, the translational application of VR-based approaches requires careful consideration of methodological limitations, including cybersickness, hardware latency, and ecological validity, to ensure robust and generalisable outcomes.

Background:The integration of virtual reality (VR) technologies into clinical rehabilitation and diagnostics is rapidly expanding, yet the neurophysiological mechanisms of their influence on spinal motor circuits remain poorly understood. This pilot study assessed the modulation of spinal reflex excitability during exposure to specific immersive audiovisual stimuli delivered via a virtual reality headset, compared to classical neuromodulation paradigm. Materials and methods:Twenty-one healthy volunteers completed a within-subject design. The H-reflex and M-response parameters of the soleus muscle were recorded at rest, during the Jendrassik maneuver, and in three VR scenarios ("roller coaster," "horror," and "relaxation"). Autonomic responses were assessed using RR interval duration and RMSSD. Statistical analysis was performed using nonparametric methods for repeated measures. Results:H-reflex thresholds remained stable across all conditions (q > 0.1). H-reflex amplitude was significantly modulated: the Jendrassik maneuver caused bilateral facilitation of the reflex (q = 0.10 and q = 0.09 for the right and left legs, respectively), while VR stimuli designed to elicit emotional responses induced suppression (a significant reduction was observed in the non-dominant leg, q = 0.06, with a similar non-significant trend in the dominant leg). M-response parameters remained unchanged, indicating the stability of peripheral conduction. Conclusion:These preliminary results suggest that the specific immersive audiovisual stimuli tested in this study can selectively modulate spinal reflex excitability via central descending pathways rather than peripheral mechanisms. The results of this preliminary research provide a foundation for the design of future investigations.

Immersive virtual reality (VR) technologies are being increasingly applied in clinical settings, physiotherapy, and neurorehabilitation due to their potential to modulate neurophysiological functions. However, the mechanistic basis of VR’s effects on human motor systems, especially the impact of emotionally charged VR experiences on segmental spinal reflex excitability, remains unclear. This study aimed to compare the effects of immersive VR stimulation with different emotional tones, the Jendrassik maneuver, and transcranial magnetic stimulation on spinal motor center excitability in healthy adults. H-reflex and M-response amplitudes in the soleus muscle were measured during tibial nerve stimulation under control conditions, during the Jendrassik maneuver, subthreshold magnetic stimulation, and while participants viewed VR videos evoking fear, excitement, or relaxation. The experimental design randomized condition order for each participant. The principal finding was that emotionally salient VR content, particularly scenes inducing fear, produced clear lateralized effects on the spinal motor system. Specifically, inhibitory effects on reflex excitability were observed in the dominant limb, while facilitatory changes occurred in the non-dominant limb. These patterns suggest that immersive VR may differentially engage descending modulatory systems, influencing both sympathoadrenal and corticospinal pathways. In contrast, traditional neuromodulatory interventions did not alter reflex parameters compared to control. The results highlight the unique multimodal influence of immersive VR on sensorimotor regulation and support its incorporation into advanced neurorehabilitation protocols. ### Competing Interest Statement The authors have declared no competing interest.

The study was devoted to the assessment of postural stability in female athletes involved in rhythmic (n = 17), artistic (n = 20) gymnastics and non-athletes (n = 19). The main objective was to identify the features of the center of pressure (CoP) oscillations in female and non-athletes under various conditions of activation of visual and somatosensory inputs. The method of computer stabilometry was used on the automated complex “Stabilan-01-5”. To assess postural stability, the parameters of the stabilographic test were analyzed: linear velocity of CoP movement (ALV, mm/s), angular velocity of CoP movement (AAV, deg/s) and ellipse area (ELLS, sq. mm), the Romberg coefficient was calculated. Spectral analysis of stabilographic signals was conducted. The participants performed tests in a normal stance on a hard and soft surface with their eyes closed and open. The results showed that CoP oscillations in female and non-gymnasts in a calm stance were comparable, but differences were observed on a soft surface. Rhythmic and artistic gymnasts demonstrated better postural stability indicators, which is explained by their ability to integrate proprioceptive and visual signals. Spectral analysis showed smaller fluctuations in the high-frequency range in both rhythmic and artistic gymnasts, which indicates the formation of specific motor and neuromuscular strategies in them. It was also found that rhythmic gymnasts were more dependent on visual control to maintain postural stability, which is probably due to the need to accurately assess the distance and body position when performing elements specific to this sport. The results obtained can serve as a basis for developing individual training programs taking into account sensory integration and movement control in different groups of athletes.

To reduce the duration of the recovery period after space expeditions, as well as high-quality effective therapy of conditions associated with physical inactivity on Earth, it is necessary to understand the mechanisms of adaptive rearrangements of morphofunctionally different motor systems at all levels of their organization. The aim of the study was to assess the functional condition of the central and peripheral links of the neuromotor apparatus of the rat calf muscles under conditions of readaptation to the action of the support reaction force and axial loads after simulated gravitational unloading. The study used electromyographic testing methods and also determined the wet and dry weight of the soleus and tibialis anterior muscles. The experimental results showed significant changes in the parameters of reflex and motor responses of the studied muscles. The recorded data indicated a decrease in the reflex excitability of the spinal motor centers on the 1st day of the readaptation period and its increase at the following stages: on the 3rd day for the soleus muscle, on the 7th day for the tibialis anterior muscle. Significant transformations of the functional condition and peripheral parts of the motor systems were also observed, as well as a gradual recovery of muscle weight. More pronounced changes and a longer recovery period were recorded during testing of the slow posterotonic soleus muscle. The information obtained can be useful for developing new and improving existing strategies for motor rehabilitation.

Autism, or autism spectrum disorder (ASD), is a multifactorial disease that is characterized not only by disorders of the psycho-emotional state and social interaction, but also by somatic dysfunctions. A number of studies have also reported changes in the musculoskeletal system in patients with ASD. In this work, by the method of video analysis of movements, we demonstrated a decrease in horizontal and vertical motor activity, in addition, deviant movements were recorded, which indicates a violation in locomotor activity and increased anxiety in rats with a valproate model of autism. However, a mechano-myographic study did not reveal significant changes in the contractility parameters of isolated skeletal muscles of rats with the ASD model. Thus, it can be concluded that general differences in movement may be an independent factor in the diagnosis of autism. A more thorough study using a larger sample and detailed kinematic analysis can help in further assessing the variability of motor functions as a potential diagnostic and prognostic marker of ASD.

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.

Transcutaneous spinal cord stimulation (tSCS) is a promising noninvasive alternative to epidural stimulation. However, further studies are needed to clarify how tSCS affects postural control. The aim of this study was to investigate the effect of transcutaneous cervical spinal cord stimulation on postural stability in healthy participants via computerized stabilization. The center of pressure and the frequency spectrum of the statokinesiogram were assessed in 14 healthy volunteers under tSCS conditions with frequencies of 5 Hz or 30 Hz, subthreshold or suprathreshold stimulus strength, open or closed eyes, and hard or soft surfaces in various combinations. The results revealed that not all the changes in the center of the pressure oscillations reached statistical significance when the tSCS was used. However, tSCS at a frequency of 30 Hz with a suprathreshold stimulus strength improved postural stability. The use of subthreshold or suprathreshold tSCS at 5 Hz led to a shift of 60% of the signal power to the low-frequency range, indicating activation of the vestibular system. With tSCS at 30 Hz, the vestibular component remained dominant, but a decrease in the proportion of high-frequency oscillations was observed, which is associated with muscle proprioception. Thus, transcutaneous electrical stimulation of the cervical spinal cord may be an effective method for activating spinal cord neural networks capable of modulating postural control.

Despite the growing enthusiasm for the use of virtual reality in the clinic, some authors emphasize that a clear understanding of its effectiveness in cognitive and motor rehabilitation is lacking. The aim of this study is to evaluate the effects of virtual reality on postural stability and balance recovery in healthy subjects with different cognitive profiles and to identify how increasing the complexity of a postural task by using virtual reality affects balance maintaining. To assess the postural stability of the subject before, during and after viewing the video sequence in virtual reality goggles, we used the method of computer-assisted stabilometry and found the correlation between the scores on the cognitive style of field-dependence/field-independence and vector and dynamic stabilometric indices.

Introduction. Traumatic spinal cord and peripheral-nerve injury is associated with release of proinflammatory cytokines and chemokines, which may stimulate neuronal activity. Adenosine triphosphoric acid (ATP) is an important pain mediator involved in the acute and chronic neuropathic pain development. Its excessive release from primary injured tissue leads to activation of P2-receptors, which may further start secondary injury mechanisms. Although the effects of ATP on the peripheral nervous system are relatively well studied, the pathophysiological role of purinergic signaling after spinalization remains unclear. The study was aimed at assessing the post-spinalization effects of P2-receptors on the contractile characteristics of rat skeleton muscles. Materials and methods. The objects of the study were the soleus muscle, the extensor digitorum longus (EDL) muscle, and diaphragm in intact rats and spinalized rats. Seven days after laminectomy followed by spinal cord transection, animals were anesthetized, exsanguinated, and their muscles with nerve stumps were isolated. Contractile response parameters were recorded using mechanomyography (MMG). To study effects of ATP on ligand binding, ATP was added to a bath and mechanical responses in the rat muscles were assessed 7 min after. After washing with Krebs–Henseleit solution, the preparations were incubated with suramin solution for 20 min with subsequent ATP application. Then the mechanical responses in the muscles were again recorded. Statistical significance was assessed using Student's t-test for independent (unpaired) and paired samples. Results. We found a significant (p 0.05) decrease in the modulating activity of ATP, as the main endogenous signaling agent, in the cholinergic synapse of the soleus muscle from 32.4 to 5.8% and from 13.7 to 5.6% for the EDL muscle after the spinalization (spinal cord injury at the Th6–Th7 level) compared with intact animals. No such dramatic changes were observed in the diaphragm. Conclusions. Abnormal ATP-mediated modulation of neuromuscular transmission demonstrated in this study supports the involvement of purinergic signaling in the neurotrophic control and functioning of various motor units.

Aim. The objective of this study is to construct a biomechanical model of lunges in professional volleyball athletes to evaluate the functionality of the ankle joint. Materials and methods. The study participants comprised professional volleyball players aged 14 to 18 years and non-athletes aged 18 to 23 years, serving as the control group. Informed consent was obtained from all participants who were appraised of the testing process. The biomechanical model was developed using the Vicon Nexus program, with reflective markers placed at key points of the ankle joint. Movement amplitude in the ankle joint was recorded using six Vicon MX cameras. Results. The professional volleyball athletes exhibited a broader range of motion in the ankle joint during dorsiflexion compared to the control group. The eccentric contraction of the plantar flexor muscles of the ankle joint may contribute to a reduction in supportive force when the forefoot approaches the ground at a larger angle, as opposed to a smaller angle. Conclusions. Our findings suggest that professional volleyball athletes use the ankle joint more effectively, a phenomenon potentially linked to their specific volleyball training and experience.

Abstract Backgroundː The aim of this study was to compare changes in plantar pressure distribution during normal stance lunges and service by professional badminton players. Methodsː The study involved 12 badminton players. The Tekscan HR pedobarographic platform (USA) was used to record data. Resultsː The results showed that both the forefoot and the hindfoot were loaded differently depending on the stage of the delivery being performed or the posture adopted. In the area of the midfoot, metatarsals and toes of the left foot, the peak pressure was lower, and the highest value was in the 3rd metatarsal during a calm stance. An analysis of changes in pressure on the foot after loading, however, relative to the initial stance showed a trend in the distribution of load on the outer surface in the left foot. On the right foot, in contrast, toe use decreased by 50%, but heel support increased by 20%, and midfoot pressure increased by 20%. During the delivery in the swing phase, there was an increase in pressure in the area of the heel of the unsupported leg. In the lunge phase, the pressure was distributed over the entire plantar surface, however, the pressure distribution remained uneven with an area of greater pressure in the heel and lateral part of the metatarsus. Conclusionsː It is recommended to introduce exercises into the training process aimed at preventing and correcting the correct position of the feet in order to reduce the risk of injuries to the ankle and knee joints.

We studied the neuroprotective effect of local application of methylprednisolone in combination with a block copolymer after contusion spinal cord injury in rats. Histological analysis of the spinal cord showed that delivery of a complex of methylprednisolone with a block copolymer reduced the volume of white and gray matter lesions. An increase in the amplitude of the evoked response of the gastrocnemius muscle was observed during epidural stimulation of the spinal cord 6 h after the injury. The maximum amplitude of the muscle response was greater in the group with local delivery of the methylprednisolone complex with the polymer 72 h after the injury. The obtained results demonstrate the neuroprotective effect of the local administration of the complex and allow to make positive prognosis for the recovery of the sensorimotor functions in rats.

Monomelic amyotrophy, also known as Hirayama disease, is a rare neurological disorder characterized by focal and latent onset of upper limb weakness and atrophy in the absence of sensory deficits, bulbar or pyramidal signs. It usually occurs in young patients. The disease usually begins unnoticeably and progresses slowly, and can manifest itself as unilateral or asymmetrical weakness, as well as atrophy of the distal upper limb. Sensory disturbances, reflex changes and signs of lesions of lower motor neurons are rare. This article describes a case of a patient with complaints of weakness not only in the upper but also in the lower extremities.

Aim. The paper was aimed at evaluating the displacement of the center of pressure during the Romberg test and the "Target" test before and after exercise in skilled badminton players and nonathletes. Materials and methods. Postural balance was evaluated during the preliminary test before and after functional exercise (45 squats per minute). The following parameters were investigated: the quality of balance, the average linear CoP oscillation velocity, the average linear CoP displacement velocity, the standard deviation of the center of pressure in the frontal and sagittal planes, and the ellipse area. Results. The quality of balance decreased in both athletes and non-athletes in the "Target" test and in the test with closed eyes. Moreover, badminton players had worse postural balance with closed eyes compared to nonathletes. Functional exercise resulted in decreased postural balance in non-athletes, and the ankle strategy was replaced by the hip strategy while maintaining balance. In general, badminton players had better balance in the "Target" test. Conclusion. The postural balance of badminton players significantly differs from that of non-athletes. The visual analyzer is responsible for maintaining postural balance in badminton players. In athletes, the existing neuromuscular regulation of postural balance leads to stabilization in the sagittal plane with increased difficulty of postural tasks.

Spinal cord injuries must be treated as soon as possible. Studies of NASCIS protocols have questioned the use of methylprednisolone therapy. This study aimed to evaluate the effect of local delivery of methylprednisolone succinate in combination with a tri-block copolymer in rats with spinal cord injury. The experiments were conducted in accordance with the bioethical guidelines. We evaluated the state of the motor centers below the level of injury by assessing the amplitude of evoked motor responses in the hind limb muscles of rats during epidural stimulation. Kinematic analysis was performed to examine the stepping cycle in each rat. Trajectories of foot movements were plotted to determine the range of limb motion, maximum foot lift height, and lateral deviation of the foot in rats on the 21st day after spinal cord injury. We have shown that the local application of methylprednisolone succinate in combination with block copolymer leads to recovery of center excitability by 21 days after injury. In rats, they recovered weight-supported locomotion, directional control of walking, and balance. The proposed assessment method provides valuable information on gait disturbances following injury and can be utilized to evaluate the quality of therapeutic interventions.