Thanks to new 3D imaging techniques, a study of 17 astronauts on the International Space Station (ISS) published in the journal Scientific Reports shows that recovery is still incomplete after a year.
Very long recovery
The work began in 2015 at the initiative of Steven Boyd, director of the McCaig Institute for Bone Health at the University of Calgary in Canada. Along with his colleagues, they imaged the skeletons of 14 men and three women before their spaceflight, when they returned to Earth, and then six and 12 months after they landed.
Specifically, they scanned the bones of the tibia (which supports almost all of the body’s weight) and the radius (forearm) to assess their density and resistance to fracture. When calculating the effects of weightlessness and physical exercises practiced back on Earth.
Conclusion: One year after the flight, 16 astronauts showed incomplete regeneration of the tibia, which lost up to 2% of its bone density compared to the pre-flight period. Prolonged stay in orbit (6 to 7 months) can damage bone structure. After 12 months, nine of the astronauts had not fully recovered. A decade of bone loss or more damage on Earth.
22 hours in bed
“We also show that bone architecture is permanently altered,” says Dr. Steven Boyd, co-author of the study. “Think of the Eiffel Tower and all its metal rods: in space, we lose some of its rods. When we return to Earth, we can repair the rest, but we will not make new connections”, the researcher continues.
“Microgravity [l’apesanteur]it’s a very severe physical inactivity,” comments Guillemette Gauquelin-Koch, head of space medicine at CNES. “Even if it’s two hours a day of sport, the other 22 hours are like you’re lying in bed,” says a doctor who wasn’t involved in the study.
Residents of the ISS have had a new machine developed by NASA for a few years, Ared (advanced resistive exercise device), which applies resistance similar to gravity to the body, allowing leg curls, biceps , stomach … “We want. “Do more of these types of exercises to reduce bone wear and tear,” suggests Steven Boyd.