How Structural Problems cause Back Pain?

Disc protrusion is a common cause of sciatica.

The spinal nerves normally have room to slide up and down inside  spinal column whenever body moves.

Cause: 

 a disc bulge can cause referred lower limb pain by protruding into  spinal column and pressing against spinal nerves. This hampers their movement.

• Disks show signs of wear and tear with age. Over time, disks dehydrate and their cartilage stiffens.
• These changes can cause  outer layer of the disk to bulge out fairly evenly all the way around its circumference  so it looks a little like a hamburger that’s too big for its bun.