Karate and Back Pain - Update

It's been about two months since I started to get lower back pain. I had hoped, in the absence of an injury, that it was caused by general strain from using new muscles and making new movements. I did three things:

1. Ensured I was in the correct stance without over arching my back
2. Did some yoga with focus on exercises for the lower back. I try to do 15 minutes most nights
3. Carried on with karate as usual

I'm relieved to find that a combination of these has worked. I now get the occasional ache after a hard session, but I'm better. So it probably was all due to being previously unfit and not having enough muscular support. From now on, I hope that being stronger and fitter along with the symmetrical focus on strengthening the core that goes with karate, will actually protect me from lower back problems in the future.