E. V. Fomina

Russian Countermeasure Systems for Adverse Effects of Microgravity on Long-Duration ISS Flights.

INTRODUCTION The system of countermeasures for the adverse effects of microgravity developed in the USSR supported the successful implementation of long-duration spaceflight (LDS) programs on the Salyut and Mir orbital stations and was subsequently adapted for flights on the International Space Station (ISS). From 2000 through 2010, crews completed 26 ISS flight increments ranging in duration from 140 to 216 d, with the participation of 27 Russian cosmonauts. These flights have made it possible to more precisely determine a crew-members level of conditioning, better assess the advantages and disadvantages of training processes, and determine prospects for future developments.

Evolution of Russian Microgravity Countermeasures.

INTRODUCTION Countermeasures to prevent or partially offset the negative physiologic changes that are caused by the effects of microgravity play an important role in supporting the performance of crewmembers in flight and their safe return to Earth. Research conducted in Russia on the orbital stations Salyut and Mir, as well as simulation experiments on the ground, have demonstrated that changes that occur during extended spaceflight in various physiologic systems can be prevented or significantly decreased by using countermeasures. Hardware and techniques used on the ISS have been substantially improved to reflect the experience of previous extended missions on Russian orbital stations. Countermeasures used during early ISS missions consisted of the U.S. treadmill (TVIS), cycle ergometer (ВБ-3), a set of resistance bands, a postural muscle loading suit (Penguin-3), electrical stimulator (Tonus-3), compression thigh cuffs (Braslet-М), a lower body negative pressure (LBNP) suit (Chibis), a lower body g-loading suit (Kentavr), and water/salt supplements. These countermeasures are described in this article.

The Russian system of preventive countermeasures: Its present and future

The study discusses Russia’s system of preventive countermeasures and its general principles based on a successful experience accumulated by many crews of long-duration missions on Russian space stations. The preventive system tested during the exploitation of the International Space Station (ISS) was described in detail. For example, differences in training workouts performed by cosmonauts allowed specialists to distinguish two exploitation phases on the ISS. The recorded locomotion workouts performed by cosmonauts displayed departures from the onboard documentation. The concluding section of the paper discusses prospects for developing a system of preventive countermeasures for interplanetary missions.

One-Year Mission on ISS Is a Step Towards Interplanetary Missions

BACKGROUND in the 1990s Russian cosmonauts performed six long-duration missions on Mir that went from 312 to 438 d. In 2015 a mission on the International Space Station that continued for 340 d, 8 h, and 47 min was successfully accomplished. It was a joint U.S./Russian mission completed by Scott Kelly and Mikhail Kornienko (KM). METHODS The intensity of in-flight physical exercises and postflight motor changes were measured in KM and in the six cosmonauts who made shorter flights (173.3 ± 13.8 d) on ISS while using similar countermeasures against the adverse effects of microgravity. RESULTS It was found that both parameters varied similarly in spite of the difference in the duration of ISS missions. KM maintained adequate physical performance throughout the entire flight; moreover, the level of postflight changes he displayed was comparable to that recorded in the group of cosmonauts who completed 6-mo missions on ISS. DISCUSSION In summary, the 1-yr mission has clearly demonstrated the high efficacy of the countermeasures used by KM.Fomina EV, Lysova NYu, Kukoba TB, Grishin AP, Kornienko MB. One-year mission on ISS is a step towards interplanetary missions. Aerosp Med Hum Perform. 2017; 88(12):1094-1099.

Comparative efficiency of different regimens of locomotor training in prolonged space flights as estimated from the data on biomechanical and electromyographic parameters of walking

Biomechanical and electromyographic characteristics of locomotion were studied before and after a space flight on days 3, 7, and 10 after landing in 18 participants of prolonged space missions on board the International Space Station. It has been shown that microgravity causes significant changes in biomechanical and electromyographic characteristics of walking, such as a decrease in the amplitude of angular displacement in leg joints, a decrease in the double step length, and an increase in the electromyographic costs of locomotion. It has been also shown that interval locomotor physical training, such as alternation of running and walking, in prolonged space flights prevents an increase in the physiological costs of locomototions after a space flight and provides more efficient maintenance of the neuromuscular system’s performance after a flight. Cosmonauts who performed interval locomotor training had fewer changes in biomechanical and electromyographic characteristics of walking.

Ground reaction force values in cosmonauts during locomotor exercises on board the International Space Station

Optimal methods for the prevention of negative impact of weightlessness have been developed based on the concept of Kozlovskaya, which states that support afferentation plays a trigger role in the development of the hypogravity motor syndrome. In this study, the maximal vertical ground reaction force (GRF) values were analyzed when locomotor training was performed on a BD-2 treadmill in long-term spaceflights. The study involved 12 cosmonauts. Recorded segments of the locomotor training (4554) performed in active (motor-driven) and passive (non-motor-driven) modes of BD-2 belt motion were analyzed. The data were analyzed by the methods of correlation and regression analysis and the nonparametric Mann–Whitney test. It was found that when running, regardless of the treadmill modes, an increase in the axial load by 1 kg was associated with a more than 1-kg increase in GRF; during walking an increase in GRF was less than 1 kg. As the speed increased, the GRF values increased most quickly when running in a passive mode and most slowly when walking in a passive mode. The GRF values in different BD-2 modes depended on both individual parameters of cosmonauts and locomotion types (walking or running). Our data can be the basis for the individualization of locomotor training onboard the ISS.

Adaptive immunity as an indicator of optimum physical loads during 520-day isolation

High stress level in the mechanisms responsible for adaptation to physical work affects the human immune system. Therefore, the effectiveness of countermeasures of reduced physical activity was studied using some parameters of the immune system. Our purpose was to examine how different types of exercises can modify physical performance and immune function in six subjects volunteered for Mars-500 simulation study. During the study, the resistance and cyclic training alternated over the period of about two months. According to the design, training was interrupted twice by an interval of approximately one month. The training plan was developed so that the initial and final stages of isolation could not impair the effectiveness of training. The cyclic training included running on the motorized and non-motorized treadmill and bicycling. Resistance exercises were performed using the MDS multifunctional exercise machine, expanders, and the Galileo 2000 vibration plate. Physical performance was assessed by the criteria of maximal voluntary effort, incremental locomotion, and bicycle exercise tests. Analysis of the quantitative and functional properties of effector cells of both innate and adaptive immunity was employed to investigate the immune status of subjects. Due to the plan of physical training, the level of physical performance in isolation was better than during the baseline data collection, although the intervals caused a considerable decrease in performance. Comparison of immunograms with the baseline ones showed positive changes: the number of naive CD4+Т-cells (CD4+CD45RA+) increased significantly. The functional activity of adaptive immunity did not reduce during isolation; on the contrary, the ability of T cells to express the early activation marker CD69+ on the surface was increased. The immune status parameters assessed in the subjects in the second half of the isolation period indicate that the proposed physical loads were adequate. In addition to retention of the baseline level of, or improvement in, physical performance, positive activation of the T component of adaptive immunity was observed.

Comparative analysis of preventive efficacy of different modes of locomotor training in space flight

According to the results of the experiment performed on board the International Space Station with participation of 15 Russian cosmonauts, comparative analysis of efficacy of two models of preventive measures used by the Russian members of long-term space missions is carried out: intense interval training in the aerobic–anaerobic power zone (recommended model) and continuous low-intensity exercises in the aerobic power zone of muscle activity energy supply. Interval training in space flight provided the maintenance of the level of physical performance close to the pre-flight level as indicated by the maximum running speed, physiological value of work, and the lactate level after performing the standard load. We describe putative mechanisms of counteraction to adaptive rearrangement of the propulsion system in zero gravity and expand understanding of the laws governing human body’s interaction with Earth’s gravitational field. The research results presented in this paper show the high preventive efficacy of interval training compared with regular aerobic training, which is very important now in the time of searching for means and methods of prevention of hypogravitational alterations during interplanetary missions.

Memorization of sequences of right and left hand movements in right- and left-handers: Vector coding

Using studies of the right and left hemisphere’s specialization for positional and vector coding, we analyzed the errors made by right- and left-handers while reproducing sequences of right and left hand movements in a task that activates vector coding by changing the order of movements in memorized sequences. The task was performed first with one hand (starting) and then with the other (continuing). Both right- and lefthanders were found to use information about previous movements of the starting hand only when the dominant hand was starting. After changing the hand, right-handers used information about previous movements of the continuing hand, while left-handers did not. The results were compared with data from earlier experiments wherein positional coding was activated. The comparison showed that vector coding was predominantly involved in memorizing sequences of movements made by the dominant hand, while positional coding was used in the case of the opposite hand in both right- and left-handers. Patterns of errors after changing the hand differed between right- and left-handers, and the conclusion was made that skills are transferred in different ways in right- and left-handers, depending on the type of coding.

Effectiveness of Different Training Programs for Physical Performance Maintenance under the Condition of Low Motor Activity

Investigations made by the World Health Organization have shown that lack of physical activity and sedentary lifestyle are among ten major causes for death and disability. Typically, studies of the negative effects of reduced physical activity and their prevention face difficulties of providing standard conditions. These issues were obviated successfully in the Mars-500 experiment on simulation of a space exploration mission. The sample of subjects consisted of six volunteers from Russia, France, Italy, and China, who were isolated in a limited space for 520 days. To prevent the negative effects of low physical activity, the volunteers performed resistive and cyclic exercises in different periods of isolation. The study was designed with two pauses in the training program. Physical performance was evaluated with an incremental loading test, maximal voluntary effort test (Russian–Austrian MDS resistive exercise system), and PWC-170 (bicycle ergometer). The level of physical performance of the subjects in this experiment never degraded to below baseline values. The proposed training system comprising different kinds of exercise ensured stability or improvement physical performance as compared with the baseline level.