Spinal stenosis results from new bone and soft tissue growth on the vertebrae, which reduces the space in the spinal canal. When the nerve roots are pinched, a painful burning, tingling and/or numbing sensation is felt from the lower back down to the legs and sometimes all the way to the feet.
In a healthy spine, the spinal canal has a rounded triangular shape that holds the spinal cord without pinching. Nerve roots leave the spinal canal through openings called nerve root canals which are also free of obstruction.
New bone growth within the spinal canal causes compression of the nerve roots, which leads to the pain of spinal stenosis.