I can personally vouch for the effectiveness of a morning routine of 15 minutes of exercise at home, targeting the pelvic muscles. The only equipment required is a floor mat, if the floor is hard. I started gently and naturally progressed to a higher level, taking the attitude that there is no hurry, because I'm going to be doing this for the rest of my life, so there is plenty of time to progress. My initial routine was just lying on my back trying to tighten my pelvic muscles without hurting. Three years later I'm up to front/back/left/right planks interleaved with stretching.
I don't mean to be smug, as back pain really is an individual thing. There's an element of searching for what works, and I was lucky in that I was pointed directly towards an effective treatment.
This result was science based, in that I was treated by a general practitioner who specialised in back pain and insisted on an evidence based approach. (This doctor also wrote the manual for NSW's worker's compensation scheme and lectures at a major university on the topic.)
Edit: My doctor's rule was "pain free exercise". Go as far as you can, but stop if hurts. A test of whether you've really overdone it is whether the new pain goes away overnight. He also reckoned that it would be difficult to do a further injury whilst doing exercises, as the pain would make me self limiting.
Further edit: My initial physio, and a cortisone injection, at the time of injury, weren't aimed at a long term fix, but at providing enough temporary pain relief to begin exercising.