Any sort of joint pain is an extremely complex phenomena, and back pain in particular is one of the most complex. It's almost never a case of "this mechanical structure was injured resulting in this pain". There are tons of studies out there showing a significant percentage of the population has disc herniation and zero pain while another significant percentage of the population has serious back pain but no structural injury visible on a scan.
I'm dealing with this personally in the contest of a shoulder injury diagnosed as a torn labrum. My research has turned up a number of NIH studies showing that something like 70% of the population over the age of 40 will show a torn labrum on an MRI regardless of whether they have any symptoms and concluding that the tear showing on the scan likely has absolutely nothing to do with the acute cause of the recent pain.
I'm dealing with this personally in the contest of a shoulder injury diagnosed as a torn labrum. My research has turned up a number of NIH studies showing that something like 70% of the population over the age of 40 will show a torn labrum on an MRI regardless of whether they have any symptoms and concluding that the tear showing on the scan likely has absolutely nothing to do with the acute cause of the recent pain.