I'm also waiting for Knotted's answer. I hurt my back a few years ago. I currently stretch twice a day and go to the chiropractor once a month. I was going to suggest some yoga, stretching and strengthening for the area. My pelvis is twisted and tilted and my lower back is the first to give out on long rides. However, overall we believe cycling is helping with core strength and loosening my hamstrings, so I just have to take it slow while I build each summer. Good luck.
"Well-behaved women seldom make history." --Laurel Thatcher Ulrich
'09 Trek WSD 2.1 with a Brooks B-68 saddle
'11 Trek WSD Madone 5.2 with Brooks B-17