Highlights of the story
Astronauts can temporarily increase height by 2 inches but suffer muscle loss and back pain
Other exercise-related countermeasures may help with pain and muscle loss
Six months on the International Space Station can be a pain in the back for astronauts. While they may gain up to 2 inches in height temporarily, that impact is accompanied by a weakening of the muscles that support the spine, according to a new study.
Astronauts have reported back pain since the late 1980s, when space missions lasted longer. Their flight medical data shows that more than half of US astronauts have reported back pain, especially in their lower back. Up to 28% said it was moderate to severe pain, sometimes lasting the entire duration of their assignment.
Things don’t improve as they return to Earth’s gravity. During the first year after the mission, astronauts were 4.3 times more likely to have a herniated disc.
“This is kind of a problem,” said Dr. Douglas Chang, first author of the new study and an associate professor of orthopedic surgery and chair of the department of physics and rehabilitation services at the University of California San. ongoing topic. Diego Health. “So this study is the first to just take it from an epidemiological description and look at the possible mechanisms for what’s happening to the backs of astronauts.”
Much attention has been focused on the intervertebral discs, the spongy shock absorbers located between our vertebrae, as the culprit for the back problems faced by astronauts. But new research goes against that thought. In this study, funded by NASA, Chang’s team observed little or no change in the discs, their height or bulge.
What they observed in the six astronauts who spent four to seven months on the ISS was terrible degeneration and atrophy of the supporting muscles in the lumbar (lower) spine, Chang said. These muscles are the ones that help us stand, walk, and move our upper extremities in environments like Earth, and also protect discs and ligaments from strain or injury.
In the case of microgravity, the torso lengthens, most likely due to spinal inactivity, in which the spinal curvature is flattened. Astronauts also don’t use the muscles in their lower back because they don’t bend over or use their lower back to move, like on Earth, Chang said. This is where the pain and stiffness happens, like when astronauts stay in a body cast for six months.
MRI scans before and after the mission showed that the astronauts lost 19% of these muscles during their flight. “Even after six weeks of training and recovery on one Earth, they only recovered about 68% of the loss,” explains Chang.
Chang and his team consider this a serious problem for long-term manned missions, especially considering that a trip to Mars could take eight or nine months just to reach the Red Planet. That trip, and the astronauts’ potential time in Mars’ gravity – 38% of the surface gravity on Earth – creates the possibility of muscle atrophy and functional decline.
Future research by the team will also look at reported neck problems, where there may be more cases of muscle atrophy and slower recovery times. They are also hoping to partner with another university for in-flight spinal ultrasound, to see what happens to astronauts while they are on the space station.
Because no one likes back pain and muscle loss, Chang suggested countermeasures should be added to astronauts who train for two to three hours on the space station each day. While their exercise machines focus on a range of issues including cardiovascular and bone health, the team believes astronauts need to include a core stretching program as well. focus on the spine.
In addition to the “fetal hug,” which astronauts use in microgravity to stretch the lower back or relieve back pain, Chang also recommends yoga. But he knows that’s easier said than done.
“A lot of yoga exercises rely on the effects of gravity, such as the downward facing dog, where gravity can stretch the hamstrings, calf muscles, nape, and shoulders. When you remove that, you may not get the same benefit.”
Any machines on the space station must be designed with regard to their weight, size, and even the reverberation they can produce on the station.
Chang and other researchers discussed with a virtual reality group various exercise programs that would allow astronauts to invite friends, family, or even Twitter followers to join them. a virtual workout, making their daily repetitions more fun and competitive.
One of Chang’s teammates felt this pain. Dr. Scott Parazynski was the only astronaut to reach the summit of Everest. He suffered a herniated disc after returning to Earth from the ISS. Less than a year later, when he tried to climb Everest for the first time, he had to land by plane. After a long recovery, he finally made it to the top. Now, he talks to current astronauts about ways they can contribute to their health studies in zero gravity.
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Keeping the astronauts healthy and fit is the least they can do, says Chang.
“When a crew came back, they said on one side of the space station, they saw this beautiful blue planet,” he said. “All that they hold dear to them lies on this fragile little planet. And they look out the other window and just see infinity stretch out in the dark, and they come back with a different sense of themselves and their place in the universe.
“They are all committed to advancing their knowledge of space and taking steps forward in whatever way they can for the next crew.”
https://www.cnn.com/2016/10/26/health/astronaut-back-pain-spine-health-space/index.html Space travel: Going to space is a real pain in the back