Astronauts may have no trouble moving heavy objects in the
weightlessness of space, but that doesn't mean that the experience isn't
hard on their backs that aches like they have been lifting heavy object. Astronauts on long-duration spaceflights routinely
report back pain, both during and after the flight. Now doctors think they know what's causing this. What you think can cause this pain at the back??? here is the answer to it.