Okay, I have sciatica in my lower back and hoping to stretch myself out using yoga. I have a question though, technically, my lower back issues is not from an injury. So I am wondering, in the first beginner's flow, should I stick with Downward Facing Dog or opt for Cobra? I don't seem to be having (so far) any issues between the two but I don't want to chose a pose that might aggravate my condition as opposed to helping it.