Julie, for some reason PLB deadlifts are ones that really bother my back. I have been under a chiropractor's care for 2 years, and for this video, I back off what Cathe lifts, and only do the up part, because by the time I go back down the low back is fatiguing too much and that is when I tend to injure it.
I have found that the Core Max video has been excellent for strengthing my overall core. I re-injured my back 18 months falling off a swimming starting block, and although it has been a long hard recovery, using Core Max has really made everything strong, and 2005 has been a much better year. I am not a young chick, 44 years young, so you can improve your core.