Where does back pain come from?
Low Back Pain Experiment In the weightless conditions of space, astronauts often experience some form of lower back pain. This is extraordinary since, on Earth, back pain is associated with heavy spinal load, mainly as a consequence of gravity. Scientists have therefore developed a hypothesis that lower back pain may develop without compression of the vertebrae. The explanation of the problem comes from the fact that the lower part of the vertebrae, the sacral bone, has to be kept in position between the two hipbones. And a deep ‘muscle corset’ plays an important role in this process, with the tonic postural muscles being activated when getting up in the morning and deactivated when resting. It is hypothesised that this protective mechanism does not work in space. In space astronauts’ bones lose calcium and strength, their muscles lose mass: therefore, it is thought that the deep muscle corset atrophies during spaceflight, leading to strain in certain ligaments, in particular in the lo