VERTICAL POSTURE STABILITY ANALYSIS DURING HYPERVENTILATION AND RESTRICTED MOBILITY OF MAIN BODY JOINTS IN HUMAN
The restricted mobility effect of main body joints on the posture stability during hyperventilation in young subjects (n = 50) was investigated. Vertical posture stability indexes were determined with the help of stabilography ("Stabilan-1-02", experimental design bureau "Rhythm"). The knee joint mobility limitation was performed using orthoses. Restriction of hip and spine mobility was made using attachment of wooden planks to hips, torso and head. Hyperventilation was standardized on respiratory rate (30 cycles*min <sup>-1</sup>). It is established that the restriction of the body mobility increased the amplitude and the average linear velocity of the oscillations in sagittal plane of the body in a free breathing. Fixation of joints has no considerable effect on increase of the amplitude, caused by hyperventilation; however the dispersion of body fluctuations in the sagittalny plane was higher, and in the frontal plane - is lower in the conditions of body joints mobility restriction. Fixation of joints has no additional increase of the linear oscillations velocity during hyperventilation. Thus, the presence of movable joints provides a mechanism for decreasing center pressure oscillations and increasing stability of vertical posture in the sagittal plane.