Has anyone ever experienced discomfort, when bowling, in the the region of the lower back (my left side "slide leg")? It's actually further down than that if you know what region I'm talking about. It is really putting a damper on my performance. I can hardly bend down, when releasing the ball, it hurts so much.

Do you actually slide when you release the ball or do you plant your foot?
The reason I ask is because I plant and when I start bowling a lot more than usual I get a pain in that generall area caused by the jolt of a sudden stop.