I have exactly the same thing..and im on Test/Dbol and now Test/Winstrol
definitely linked to the juice but also i agree with the guys if your back is a weak spot it will excentuate the problem. My lower back is definitely a weak area...so started doing dead lifts, hyper extensions, and good morning exercises.....has helped.
i have also started supplimenting with Taurine. I read it helps.