hamstring stretches
Stretching my hamstrings stretches the ligaments which allow the discs to bulge. That's how it was explained to me by my PT who was looking at my MRI. I found that the hamstrings can seem tight, not because they need stretching, but because the sciatic nerve is being impinged and is firing.
This is the trap that I fell into a couple of times now (but never again). When the hamstring was tight, I thought the best thing was to stretch it, and that was followed by further inflammation of the nerve, which caused the hamstring to feel tighter which led me to stretch, etc..... Several of the physical therapists in the practice that I was visiting said that the never stretch the hamstring for the very reason. I cycle about 200 miles a week and play racquetball four or five days and I don't stretch at all! Just warm up and down. My friend who is manic about stretching is in constant pain.