This condition is an irritation or compression of one or more nerve roots in the lumbar spine. Because these nerves travel to the hips, buttocks, legs and feet, an injury in the lumbar spine can cause symptoms in these areas. Sciatica may result from a variety of problems with the bones and tissues of the lumbar spinal column.
Causes (Herniated Disc)
One common cause is a herniated disc. A herniated
disc is a rupture in the fibrous outer wall of a
vertebral disc, which allows the soft nucleus of the
disc to bulge outward. This bulge can press
harmfully against a nerve root.
Causes (Degenerative Disc Disease)
Another common cause of nerve root injury is
degenerative disc disease. It occurs when a spinal
disc weakens, allowing vertebral bones above and
below the disc to shift out of position. The bones
can touch, pinching nearby nerve roots.
Causes (Spinal Stenosis)
When bones, discs or joints of the spine
degenerate, bony spurs may form and push into the
spinal canal or foramen space. This is called spinal
stenosis, and it can also create harmful pressure
against the nerve roots.
Nerve root injury may occur at any of the five
vertebrae in the lumbar spine (called the L1 through
L5), or at the level of the sacrum (the upper portion
of which is called the S1). Symptoms may include
pain, weakness, numbness and tingling, and may
vary depending on the level of the injury. For
example, an injury at the L2 level can create thigh
pain and hip weakness. An injury at the L3 level
may result in thigh pain and knee and thigh
weakness. Damage at the L4 level may cause pain
from the lower back to the foot and also foot
weakness. Damage at the L5 level can create pain
from the outer leg to the top of the foot and also
foot weakness. And finally, damage at the S1 level
can create pain from the calf to the outer foot and
also foot weakness.