Perhaps you are just arching too much.
Just started using this as described in SS DVD (it seems to describe it better than the book) About pushing up from the floor to acheive that arch in lower back. I started doing this, and have found my lower back hurts like hell.
Can someone help me with this? I don't think I have my head around the leg drive properly.
Perhaps you are just arching too much.
I arch enough to get a fist under my lower back.
I put my feet on the ground roughly in the squat stance, slightly towards my body. Then sort of push towards my body and through my buttocks into that arch (without moving the body) Is this right?
You can certainly overextend your back during a bench press, especially if you are not used to doing so. Obviously, if something hurts, don't do it. Arch your back less aggressively. As you train, you will adapt and be able to get more arching without pain. Just be patient and listen to what you back is telling you.
One thing that may cause low back soreness is not good enough warm up. However if this is first time arching then its natural that low back is sore. Usually it is better already after next bench training. Several trainees in my gym and myself included had same experience, first time after (bigger) arching low back sore and already next time no soreness.