I am fairly double-jointed so bending over from the waist is easy for me (even now with my bad hip). When I had a painful back (all of the year of 2000), I learned that I had a narrowed spot in my lower spine, and leaning forward actually took the pressure off my lower spine and helped with my pain. I also had a 4.7ish ascending aorta aneurysm that stayed stable for almost 20 years (until it was repaired during my AVS). So from my experience, I would say that bending forward from the waist seemed to have no bad effects on my aneurysm. What I did notice was, however, that bending over for more that a couple of minutes would cause the blood to seem to run to my face and cause a noticable pulsating in the blood vessels in my face and head. If I had had a brain aneurysm, I suppose bending over would have been dangerous.