For the next few weeks, the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) :envihab research facility will be home to 12 men in good health, aged between 20 and 45 years. The men are test subjects for a long-term bedrest study – they will be confined to bedrest for two months with two weeks of experimental investigations and tests. Their beds will be tilted at an angle of six degrees below the horizontal, so that their bodily fluids shift towards the upper body; the bones and muscles in their lower part of their bodies will lose strength as a result of the lack of movement. “In this way we simulate the effects of microgravity on the human body,” says Edwin Mulder, leader of the study and a scientist at the DLR Institute of Aerospace Medicine, about the study, which is being carried out by DLR on behalf of the European Space Agency (ESA). “Our volunteers are, so to speak, terrestrial astronauts.” Half of the test subjects will undergo reactive jump training several times a week, which involves lying on a specially positioned training device. “We want to see whether this very intensive training can be an effective countermeasure to the deterioration of the bones and muscles.”
Bone loss tests and the sense of equilibrium
Currently, astronauts on board the International Space Station (ISS) have to exercise for over two hours a day to minimise the negative effects of microgravity on their bodies. The intention of the study at DLR is to investigate, among other things, whether other exercises could be more suitable as countermeasures. Therefore, the test subjects in the group will be training five or six times per week primarily by making small, powerful jumps in a horizontal position – ‘reactive jumps’. “A short course of training with strong muscular focus, there has never been anything of this kind in space before,” explains Mulder. The scientists involved are carrying out approximately 90 experiments: in addition to studying the effects of inactivity on bones and muscles during the two months spent in bed, they are also investigating changes to the cardiovascular system, sense of balance, the eyes, thermo-regulation, as well as the autonomic nervous system. The test subjects will undergo regular examinations and tests.
Acquiring experience for career and study
Lucas Braunschmidt is one of the 12 ‘terrestrial astronauts selected’ – he is in good health, approximately the right age for an astronaut and interested in medical matters. During the 60 days and nights that he will be confined to bed, the bone density in his hips is predicted to deteriorate by between two to four percent. The muscles in his legs and back will deteriorate as well – the calf muscle most of all, by up to 25 percent. Braunschmidt has just successfully completed his three-year training course to become an occupational therapist and is postponing the start of his career until next year to participate in the study: “I’m looking forward to the experience”. Later, he will be treating patients who have had this very experience – confined to bed, reliant on others, with bones and muscles that need to be built up again. Braunschmidt is also planning another medical study in the future – “from the study I can learn the latest experimental methods, for example in the bone density tests, I saw my body for the first time in this state and can see how research in this area is progressing.”
Strict bedrest around the clock
Two test subjects will be admitted to the :envihab research facility each day. Their medical information will be recorded in detail and their bedrest will commence on 9 September 2015. During this phase none of the test subjects may stand up – one shoulder must remain on the mattress at all times. This rule has to be observed even when eating or taking a shower. A regular day-night routine and a vigorously controlled diet will also be applied. The temperature and air humidity will be uniformly regulated in the research module comprised of 12 single rooms. Visitors are not permitted, however communication by mobile phone and the Internet is allowed.
Long-term observation of the participants
All test subjects will be examined and tested for an additional two weeks following their time in bedrest. They will also receive rehabilitation treatment. “The bone and muscle loss will be returned to original condition after the study,” explains DLR physician Ulrich Limper, the study’s medical director. The recovery phase is particularly exciting for medical professionals. “We are investigating not only acute recovery, but also the long-term reconstruction of bones and muscles.” After their stay in :envihab, the test subjects will participate in five follow-up examinations over the next two years. “We know that bone deterioration is completely reversible, but it will be a long time, before the original condition can be reached – and we want to have a better understanding of this mechanism.”
Seeking more participants
Male test subjects between the ages of 20 and 50 are currently being sought for a second study phase at the end of January. “We need healthy participants, who know what to expect from the study, and fit in well with the team,” says Mulder. “Research can only work through cooperation between scientists and participants.” After completing an initial questionnaire, interested candidates will be invited to an informative interview. Before being selected as a test subject, however, their evaluation, through psychological questionnaires, a medical examination and psychometric interview will all need to show positive results.
Braunschmidt is taking DVDs, books and magazines along to the voluntary bedrest. “I don’t think I’ll get bored,” he says. For one thing, the showers themselves take longer than usual, and then there are the experiments – “there will be enough going on throughout the day.” His family and friends were astounded when the 22-year old told them he was going to be a test subject. “But then, I was able to better explain what was so exciting about this study.”