I think it's a bigger picture thing.
The way I understand it, the anabolic **** will get you all swolt up but it's at the expense of your joints. Your joints do not get stronger or healthier in proportion to how much stronger your muscles are. So, if I'm a skinny ***** and take a bunch of roids and turn into Barry Bonds, suddenly I can lift heavy stuff but my joints are still that of a skinny *****. Hence the joint injuries like those in the back.
I think the non-anabolic **** is used for helping injuries recover faster. I'm not a doctor but this is my 1st grade level knowledge of roids.
Whatever the case, when you start having back problems that are related to joints and discs, you're f'ed. I speak from experience. You just don't ever go back to the way you were before.