From a job in orbit to insights into everyday diseases, space could offer surprising opportunities, says Robert Millett
When Soviet cosmonaut Yuri Gagarin became the first person in space, 50 years ago, his survival was uncertain. The possible side effects of his 108-minute flight were completely unknown.
Technology has made huge advances since then. Humans now orbit Earth on a regular basis, living for six months or more on the International Space Station (ISS). But space travel is still rife with risks, and the physiological dangers of weightlessness are a primary concern.
Now, with plans for manned missions to Mars and the imminent advent of space tourism, physiotherapy seems set to play a key role in the future of space exploration.
Meanwhile on Earth, physios are already using information from space to find new treatments for everyday conditions.
Since 2000, the European Space Agency (ESA) in Cologne, Germany, has employed physiotherapist Gunda Lambrecht as part of their medical team. Her main focus is on preparing ISS crew for their missions, developing in-flight exercise programmes and organising post-flight rehabilitation back on Earth.
‘Currently we have a very Earth-centric mission support paradigm,’ says Dr Volker Damann, head of ESA medical operations.
‘We are sitting on the ground at mission control monitoring what the astronauts are doing. But I believe that in the future it will be like Star Trek – we’ll have physicians like ‘Bones’ McCoy, flying with the crew.’
Although this development is some way off, the space industry is keen to encourage a new generation of space researchers and medical experts. So ESA has joined forces with Kings College London to provide a new MSc in space physiology and health.
The first intake of students is predominantly doctors but among them is one physio, 24-year-old Huw Scott.
‘It’s an unusual route for a physio to be going down,’ Huw admits. But the course appealed to him on many levels, including the relevance of space to the wider field of physiotherapy.
‘The key principle to remember is that almost everything that happens to the body in space can also happen in bed,’ says Huw.
‘The rehabilitation that astronauts need is very relevant to older people, and there are huge implications for muscle and bone pathologies. In fact, space research could potentially give us answers for things like muscular dystrophy.’
Exposure to microgravity has a significant detrimental effect on the musculoskeletal system. Astronauts suffer muscular atrophy and a significant loss of bone density.
The microgravity environment also results in changes to the cardiovascular system, abnormal fluid shifts, vestibular changes, blood pressure irregularities and an increased risk of injury.
All of these stem from the fact that the body evolved to resist and counter Earth’s gravitational field. So when humans enter space, millions of years of evolutionary fine-tuning are thrown into disarray.
Adverse effects occur very rapidly, as the body radically attempts to adapt to weightlessness.
‘You start unloading your bones, unloading your muscles, unloading your nervous system – everything,’ says Huw.
Within two weeks, the muscles have deconditioned and the bones have entered into a dissolution phase, he says.
Approximately two per cent of bone mineral content is lost for every month spent in space and it can take astronauts eight months or more to regain their normal quota.
‘There are a few astronauts and cosmonauts who have never fully recovered,’ says Huw. ‘Even after a year or two back on Earth, the strength, quality and mineral density of their bones has never returned to normal.’
Extensive exercise regimes are completed during space flights in an attempt to counteract these physical effects. The astronauts also undergo a further period of rehabilitation back on Earth.
But when they first return from a six-month mission, they can barely stand up.
‘They suffer from orthostatic intolerance, so if they stand up for 30 seconds they faint,’ explains Huw. ‘This is also something that older people can get, or that occurs with certain pathologies or conditions.’
In terrestrial patients, this is often due to impaired cardiac function. The same happens with space crew: their cardiac muscles weaken, because the heart no longer needs to pump blood against gravity.
They also experience an upward shift of fluid in their bodies. This leads to a reduction in blood volume and the loss of up to 15 per cent of plasma and red blood cells. The loss of blood plasma affects sodium levels and the concentration of salts in the body, which in turn confuses the blood pressure regulation system. So when the astronauts return to Earth, gravity pulls the blood down to their legs and the astronauts faint.
The microgravity environment also creates major muscular imbalance. Flexor muscles begin to contract and extensor muscles weaken and lengthen. As a result the legs shrink and the body begins to return to a balled-up foetal position.
The core muscles that support and stabilise the spine also go out of balance, resulting in horizontal translation of the vertebrae – increasing the risk of nerve-root irritations and damage to the discs, muscles and ligaments.
‘Spinal elongation in weightlessness puts more of a strain upon your nerves,’ says Dr Damann. ‘So, many of the astronauts complain about back pain.’
The loss of gravitational force also weakens the muscles involved in joint protection and posture.
‘The body’s joint protection system, which normally detects very rapidly when a joint is about to exceed its limits, deteriorates very quickly in space,’ says Huw. ‘You no longer have that instinctive “Ooh, I’m going too far” so there is a huge elevation of injury risk.’
The physiological conditions astronauts experience are uncannily similar to those found in chronically ill patients and people confined to long periods of bed rest. Both groups suffer muscle and bone deterioration, cardiovascular deconditioning and postural changes.
The European Space Agency has been involved in a collaborative study with a research team based in the physiotherapy department at Northumbria University. They’re exchanging knowledge about the physiology of astronauts and chronically inactive patients.
Dr Nick Caplan, associate director of the university’s Centre for Sport, Exercise and Wellbeing Research, is heading the team.
‘Atrophy of the stabiliser, or antigravity, muscles is the focus of our current research,’ says Dr Caplan.
‘The research has a range of terrestrial applications, because similar symptoms are seen in lower-back pain patients and those exposed to prolonged bed rest.’
The parallels are so strong that researchers are now taking a closer look at the stabiliser muscles and using ‘bed studies’ to mirror the effects of microgravity. Bedridden patients are being given lumbar spine and stimuli training and compared with control groups, to see if the strength of the stabiliser muscles can be maintained.
The space industry is also keen to research conditions such as osteoporosis and gain an understanding of the underlying mechanisms involved, to help them combat the bone loss associated with microgravity.
One of the most successful treatments identified so far is vibration. Studies are showing that vibration therapy can increase the bone density of people with osteoporosis.
‘They’ve actually found that certain frequencies of vibration through the bone stimulate the osteoblasts, the bone stem cells, to regenerate and grow,’ says Huw.
On Earth, these vibrations are received via the body’s natural movements – walking, running, jumping. But in the weightlessness of space, the necessary feedback of physical impact is near impossible to attain, making this a useful area for research.
Space for jobs
What does all this mean in terms of opportunities for physios?
If private space ventures such as Virgin Galactic become popular, says Huw, there may be potential for physiotherapists to be involved in the preparation and treatment of space tourists.
The first hundred passengers scheduled to fly range from 18 to 88 years of age. Those who are less active or fit may well benefit from pre- or post-flight physiotherapy.
‘Virgin Galactic flights are only going to be in microgravity for three minutes, so people won’t experience any physiological challenges,’ says Huw. However, they will feel the weight effects of acceleration, or G-force.
‘There are huge G-forces on the way up and way down,’ he says. ‘Up to 4G on the way up and 5G on the way down – and for a normal person, that’s a lot of pressure on the body.’
Agencies such as ESA may require more physiotherapists as space travel advances, says Dr Damann.
‘The missions will become longer and we will hopefully explore the moon, Mars and beyond,’ he says.
‘There are also plans to build hotels in space, which we may see in a couple of years. As you’d expect at any good four- or five-star hotel, physiotherapists may be present. If that industry really kicks off, there may be lots of opportunities.’
In the meantime, space research may provide valuable insights that can be used to treat various conditions and applied to the care of older and bedridden people.
Additionally, the dramatic changes that occur in space serve as a radical reminder of how essential exercise and regular activity are for the body.
‘Our biology is built in such way that if we use something it increases,’ says Dr Damann. ‘And equally if we don’t use something it decreases.’
Huw Scott agrees and points out that, although space is an extreme environment, it demonstrates how rapidly the body can adapt in response to our lifestyles.
‘So many of us sit at desks for eight hours a day,’ says Huw. ‘And then we wonder why people get bad backs and muscle imbalances.’ fl
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