Zero gravity affects astronauts backs even after they land

Zero gravity affects astronauts backs even after they land

Miles above the Earth’s atmosphere, common human maladies still plague the few men and women who have been lucky enough to embark on spectacular space missions.

Astronauts have long complained of lower back pain, sometimes beginning in space flight and often lasting extended periods of time after they return to Earth. Back pain on earth is a familiar ailment, but for these astronauts, the cause is otherworldly.

Researchers writing in the journal Spine report that astronauts’ lower back pain is likely tied to muscular changes. After several months in zero gravity, astronauts have significantly smaller and less dense muscles in their trunks, neighboring their spinal columns. These paraspinal muscles were altered after at least three months outside Earth’s atmosphere, according to the data collected on the astronauts. In addition, the study also found more fatty tissue in the muscles than before the astronauts left Earth.

Repeated post-mission analyses showed the muscles regained nearly 70 percent of their pre-flight size and density within six weeks, and most shed the excess fatty tissue. But two particular muscles, those that connect the spinal column to the pelvis, stayed fatty for at least several years. Another troubling finding: after extended spacetime, astronauts have a higher risk of herniated discs in the spine.

Another, ongoing study examining how the structure of the astronauts’ backs influences function may help shed light on the complex problem of back pain and mobility issues in Earth-bound humans. Could this be another small step by astronauts that will one day lead to a “giant leap” for mankind?


Related Episodes