[QUOTE]Originally posted by Tengu51:
I can tell you that the rolls we do use move diagonally across the spine (Shoulder to hip or hip to shoulder) as opposed to directly over your head as in a summersault, which can damage your neck if done improperly.
Not all front and back rolls in the Bujinkan involve diagonal rolling as we have both front AND back sommersaults that go directly over the top. Unfortunately not all Bujinkan members are taught these types of rolls. The key is, as you allude to, is knowing how to do these properly which requires one to have proper instruction.