[Human tolerance of +Gx loads in anti-G suits during deorbiting of the "Soiuz" space vehicles]. / Perenosimost' chelovekom peregruzok napravleniia +Gx na uchastke spuska s orbity kosmicheskikh korablei tipa "Soiuz" pri ispol'zovanii protivoperegruzochnykh kostiumov.

Reported are results of the study of tolerance of the "thorax-back" g-loads (+Gx) during deorbiting of 83 total suited and unsuited cosmonauts in the period of 1997-1997. G-loads averaged 3.7 +/- 0.058 units (from 3.1 up to 5.1 units). Pneumatic gradient G-suits (PGS) Karkas and Centaur had a positive effect on the +Gx tolerance of humans following microgravity. As compared with unsuited crews returning from missions of similar duration, wearing PGS has proven to improve the general health of cosmonauts and to reduce the strain of the leg and abdominal muscles. Tight fitting of PGS abolished visual disorders due to the longitudinal component of G-loads that were registered in 6.6% of observations of unsuited cosmonauts. Sinus tachycardia was significantly weaker (P < 0.05). The authors recommend the use of the standard antiblackout Centaur suit as the efficacy of this PGS was equal to that of Karkas while its ergonomic characteristics were superior.

[Tolerance of +Gx-loads by females before and after a 120-day hypokinesia]. / Perenosimost' peregruzok napravleniia +Gx zhenshchinami do i posle 120-sutochnoi gipokinezii.

The goal of the work was to study female tolerance of g-loads before and after simulated weightlessness, and evaluate the effectiveness of countermeasures and anti-g means proposed for space flight. Centrifuge with a 7.25 m arm was used for 29 runs of 8 female subjects. The subjects were exposed to the transverse loads (+GX) at 8.2 g on a special regimen with the total run time of 9 min to simulate the ballistic descent from orbit in a SOYUZ-TM vehicle. Baseline tolerance of the females to transverse loads up to +8GX was good and satisfactory. Following 120 days of bed rest without the countermeasures or the anti-g suit g-tolerance was significantly lowered as evidenced by visual disorders in 67% of cases and exaggerated, if compared with the pre-hypokinesia levels, heart and respiration rates, i.e. 20% and 23.5%, respectively. The countermeasures and anti-g suit Centaur maintained g-tolerance at essentially the baseline level and precluded visual disorders. Results of the study speak in favor of the countermeasures and anti-g means used by the females in simulated long-duration weightlessness which can be recommended for the final phase of extended space mission.

[Tolerance of functional and exercise tests during 1-year antiorthostatic hypokinesia]. / Perenosimos't obsleduemymi funktsiona'lno-nagruzochnykh prob v usloviiakh godovoi antiortostaticheskoi gipokinezii.

During 370 days 9 healthy young volunteers were exposed to antiorthostatic hypokinesia. Group A consisting of 4 subjects performed exercises similar to those regularly made by Mir crewmembers and Group B consisting of 5 subjects did not exercise for 120 days and then performed experimental exercise regimens. It was demonstrated that the health status of men long exposed to head-down tilting can be controlled with the aid of various countermeasures. As a result of the exposure, orthostatic and exercise tolerance diminished. In view of the fact that the changes observed were more pronounced in the Group B subjects, it can be concluded that the countermeasures used were more effective in Group A subjects.