Bone atrophy affects astronauts due to lack of load in space
Can astronauts have osteoporosis? In principle, yes, even if it is not exactly in the same form as post-menopausal or age-related osteoporosis that affects those of us who haven’t been to space. The condition astronauts experience is the manifestation of bone atrophy and declining bone mineral density, caused by not being able to load their bones while in space as gravity is not present. This has been described in Wolff’s Law – the basic rule of orthopaedics that states bone adapts to what is demanded of it. Astronauts’ bones don’t experience loads while they are weightless in space and this leads to the loss of bone mineral density, just as in osteoporosis.
Osteoporosis and NASA
At a relatively early stage and when space missions began, it was noticed that astronauts suffered from decreasing muscle mass and strength as well as decreasing bone mass and bone mineral density after a longer stay in space. This had exactly the same consequences that threaten the health of older people or those affected by osteoporosis.
These problems came up for discussion for the first time in the eighties and posed a big challenge to space medicine. The American space authority, NASA, took charge to seek a solution recognising it was a serious health concern for astronauts. With plans for NASA to succeed in longer space flights, trips to the moon and even setting sights going further to Mars, they had to find a solution to astronauts losing bone mineral density when in space. Living for months with zero gravity was being planned, including trips to the new large space station ISS.
Osteoporosis – also a problem of zero gravity
Space doctors had to prepare the astronauts for a long mission and find a way to keep their bones and muscles strong and powerful. Recognising the physical and psychological demands on astronauts during space missions in zero gravity are extremely high, the doctors wanted to find a non-invasive, drug-free way to stabilise their bones. This is a key consideration as astronauts are not supposed to take any medication (or as little as possible). Any treatment using drugs can have side effects and carry risks thus a solution was sought that was natural, safe, without risk but also effective.
Astronauts can experience up to 20% loss of bone mass or bone mineral density a year - equivalent to 10 times that in a case of pronounced, untreated osteoporosis on earth. These high losses in a relatively short time were particularly worrying. The disease progressed at a much faster rate in astronauts in effect ageing their bones rapidly.
To put this in context, women affected by osteoporosis who remain untreated, can lose about 1.5% of their bone mass in the lumbar spinal region, in the hips or femoral neck within one year. An astronaut, by comparison, could lose this amount in a single month. This itself is of major concern: but imagine if an astronaut suffered a fractured leg or hip while in space or on Mars.
Vibration treatment for astronauts
The American space authority, NASA, played a crucial role in the research and development of low intensity vibration which they identified as having the potential to help astronauts mitigate bone loss while in space. Together with leading medical practitioners and biomechanics, a team from NASA worked on the LIV concept and coordinated considerable amounts of research over many years.
Professor Clinton Rubin led the NASA Vibe Project – officially entitled A Low Intensity Mechanical Countermeasure to Prohibit Osteoporosis in Astronauts During Long-Term Spaceflight » NASA. This and other NASA vibration studies aimed to overcome the problem of the loss of bone substance and muscles in experiments.
Research into the cellular effects and mechanisms was to provide an approach to the problem which supports the purpose of the musculoskeletal system – namely to maintain bone substance and ensure mobility, muscle strength and balance. The initial research (1990-2000) still worked with animals (which were not harmed) and quickly focussed on specific and low intensity load stimuli. This constituted movements with low peak loads and repeated frequently – stimuli acting on the bones and muscles. The next step was to develop a treatment device and implement the treatment on people. This in turn was followed by further investigations, studies, improvements and renewed implementation. A process over many years and with many stages. The result is a vibration platform which you stand on as it transmits stimuli to the bones. These specific, low intensity stimuli activate the body’s cells and thus contribute to maintaining and building up bones and muscles.
Vibration treatment using Marodyne LIV
It soon became apparent that such a treatment could not only benefit astronauts but also elderly people and those affected by osteoporosis who wanted to strengthen their muscle strength and bone density. Julie Robinson, a NASA scientist at the Johnson Space Centre in Houston got to the heart of the matter regarding reduced bone mineral density: “The success of manned research missions depends on finding countermeasures to tackle these effects. There are significant synergies between osteoporosis research on earth and the studies of astronauts’ bones. The research fields complement each other”. (Source: www.raumfahrer.net/news).
The statement ‘what zero gravity is to astronauts, age is to us on earth’ became known later. This is where space medicine and treatment using low intensity vibration converge. The technology, methods and associated medical results, once developed for astronauts, were increasingly refined and repeatedly subjected to new studies. Over 20 years it was revised and improved until the Marodyne LIV treatment device we see today was perfected for general medical and home use.
Astronauts and osteoporosis
Astronauts get osteoporosis! This is why the American space authority NASA supported the development of this vibration treatment. See what elderly people and astronauts have in common and why astronaut’s bones lose mass and density... » more