Intervertebral disc damage and spaceflight

Astronauts have expressed an increased incidence of back pain during spaceflight and herniated intervertebral discs (IVD) have been diagnosed upon return of Skylab and Shuttle spaceflight participants. These conditions and symptoms may be from previous back injury, but the evidence of IVD injuries raises the possibility that astronauts are at an increased risk of intervertebral disc damage during loading scenarios experienced during exploration missions (re-entry to a gravitational field and activities on planetary surfaces).

Source: Wikipedia — Intervertebral disc damage and spaceflight (CC BY-SA 4.0)