I've had back trouble now and again aggravated by skiing and other activities. Some decent stretching exercises help me alot 1. Hang fully extended from a pull-up bar or similar. Relax your abs and back as much as possible. I hang as long as I can comfortably. Inversion boots/table would also work for this but I've never used these myself. 2. Exercise ball - Lay over the top of a large air inflated exercise ball. I lay face down with my waist at the top of the ball and hand my torso down onside and legs off the other. Relax as in (1). You can also to back extensions like this once your not hurting to build you lower back.  Turn over and do sit-ups also to build core muscles. 3. Lay down on the floor face first and push up with your arms, hands directly under your shoulders, while keeping your hips on the ground. Repeat this a few times holding for 5-10 seconds each time.  Keep in mind I'm not M.D. nor Physical Therapist, this is just what has worked well for me in the past.