I get lower back pain if I'm pushing hard at a low cadence on very steep climbs. Otherwise, I'm normally spinning at a high cadence with low to medium force on the pedals.
Last year, I wanted to do winter core exercises, so I got Tom Daniel's
Core Advantage book, co-written with an experienced bike trainer/therapist.
The first part of the book discusses the theory of cycling muscles and ligaments, then has programs of bike specific stretching and core exercises that don't need any equipment other than a floor mat and a doorway.
There's a couple of pages on spinal disk injuries, but the concentration is on muscle overuse.
From the lower pack pain discussion:
...almost all muscular overuse injuries stem from certain muscles being tight and overactive while others are lengthened and weak, which causes alterered length-tension relationships in both sets of muscles. ...the root of the problem could be a pelvis that is tilted either too far forward or backward.
They have a few videos of some of the book's exercises.