BACKGROUND: Passive postural exertions are used to assess orthostatic tolerance, adaptation to antiorthostatic stress and to identify the physiological effects of prolonged supine. As it was shown earlier, Wobbling Passive Dynamic Postural impacts influence on the state of functional reserves, activating long-term regulatory systems. AIM: The purpose of paper is comparative study of the dynamics of functional indices and calculated physiological indices before and after Wobbling Passive Dynamic Postural exertions and experimental hypokinesia. MATERIALS AND METHODS: The study involved 50 conditionally healthy subjects randomly divided into two groups at a ratio of 3 to 1. The first group (38 of participants) was exposed to the Wobbling Passive Dynamic Postural impacts. The subjects were in supine position for 5 minutes and then were rotated using an automatic turntable for 10 minutes, after which they were to horizontal position for 5 minutes. The angle deflection of the turntable during the Wobbling Passive Dynamic Postural impacts was from 5 to 15 degrees above or below from the base line. The subjects of the second group (12 of participants) were supine on the turntable fixed in the horizontal position for 20 minutes, thus being exposed to voluntary experimental hypokinesia. Anthropometric indices of subjects were measured before the study; functional indices were recorded continuously throughout the test. The entire study was divided into three stages, for which the values of the calculated physiological indices were presented as averages. Statistical analysis of the differences between the measured and calculated indices was performed using nonparametric statistical tests. RESULTS: Application of both types of exertions leads to decrease of the experienced stress and more effective blood circulation, but there are expressed differences. Thus, Wobbling Passive Dynamic Postural impacts are accompanied by a decrease in heart rate, an increase in the adaptive potential, an increase in endurance, which is confirmed by statistically significant changes in the analyzed indices. On the contrary, in the voluntary experimental hypokinesia group, by the end of the 20-minute motionless lying there was a gradual increase in heart rate, decrease in endurance indices and weakening of the adaptive potential. CONCLUSIONS: The results obtained with the use of available, previously tested, physiological techniques permit to recommend wobbling passive dynamic postural impacts as a promising method for preventing the harmful effect of hypokinesia. An advanced study of changes in the microvasculature using modern equipment based on Laser Doppler flowmetry will allow verifying the obtained results.

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BACKGROUND: Reactions of human cardiovascular system to complex dynamic postural loads were under investigation by previous authors. Individual limiting mode of postural loads, i.e. alternating negative-positive periodic changes of body position angle on tilting table with regard to clinostatic position, was defined. It was demonstrated that application of oscillatory passive dynamic postural loads can cause certain hemodynamic reactions, which expression depend on postural loads dynamic characteristics and subjects primary state. AIM: Aim of the study is to develop comprehensive methodology (practice) that explores regulation mechanisms of cardiovascular, respiratory, central and autonomic nervous systems and their reactions to physiological strains with assigned properties (intensity, direction, periodicity and duration of postural loads). MATERIALS AND METHODS: 30 young healthy participants took part in the study. Physiological indicators were registered in dynamic mode synchronously with trajectory of participants motion. This study implemented common statistical methods as much as original means of analysis by integrating theory of dynamic systems. RESULTS: Evaluation of synchronously registered physiological indicators by means of instrumental and software application, in particular, postural loads protocols of various intensity and motion direction, showed that oscillatory passive dynamic postural mode allows considerable improvements in overall blood circulation and gas exchange in the lungs. These changes constitute in a rise of systemic and local blood flow without significant shift of arterial pressure, increased frequency of heartbeats and respiratory rate. CONCLUSIONS: Continuous monitoring of participants condition during complex postural loads give an opportunity for studying a set of physiological reactions and has a future implication in scientifically approved recommendations that describe practical use of postural loads as a correction technology for human health state and training.

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