Disc degeneration is a common cause of chronic low back pain. It has been believed that the discs that sit between the bones of the spine degenerate more quickly in those who put more stress on their spines. People who bend, twist and lift heavy objects frequently were expected to have more advanced disc degeneration.

The findings of the Twin Spine Study, which has studied sets of twins in Finland, may change the way that disc degeneration is understood. When comparing identical twins who had sedentary jobs to those that had jobs with heavy physical demands, there was no significant change noted in the disc degeneration. This suggests that there is a strong genetic cause of disc degeneration.