I have a lower back injury where I have two prolapsed disks L34 and L45. L34 has a disk that has been exasperpated where there is a tear. This happened a year and a half ago. I am exercising to strengthen my core. I get sudden on set of imbolizing pain down my right buttock, pain into my knee and into my ankle which feels like it is stabbing. Then there is numbness in my toes on my right foot. I have been given pain killers. But I do not know what causes this pain. Noone can tell me what and why?