by ricardo on Mon Nov 17, 2008 5:12 pm
Mine is L5-S1, that's low back also. I have to say that I don't have a lot of pain now, I don't know your condition.
I do the side exercises too (second video), not with the hole leg extended, knees bent instead. When doing this exercise, if you touch the muscles to the side of your low back you will feel that they are very tight, even more than your abs. I guess it is important to keep your trunk straight.