Sciatic Nerve Dysfunction
Sciatic nerve dysfunction is a condition in which the sciatic nerve conducts impulses abnormally. The sciatic nerve is the main nerve of the leg. Abnormalities of this nerve can impair movement and/or sensation. Sciatica is a term that describes pain along the sciatic nerve.
What is going on in the body?
The sciatic nerve runs through the leg and is the largest nerve in the body. It conducts nerve impulses to and from the following areas:
the hip joints
some of the thigh muscles
the knee and ankle joints
all the muscles of the lower leg
joints and muscles in the feet
Sciatic nerve dysfunction may affect any of these areas of the body. Most often, the nerve damage occurs when a disk in the spine ruptures. The vertebrae of the spinal column are separated by vertebral disks that act like shock absorbers. A disk is made up of two parts. The outer ring or annulus is a tough, fibrous material. The inner part or nucleus is a soft, jelly-like material. A ruptured disk occurs when the outer ring tears or breaks, allowing the jelly-like material to poke through the crack. The disk may press on the sciatic nerve.
What are the causes and risks of the condition?
There are many causes of a ruptured disk. Repeated heavy lifting is the most common cause, especially when improper lifting techniques are used. Many people who have a ruptured disk are involved in manual labor jobs. Other risk factors for disk rupture include:
activities, such as driving a car, that pass vibrations along the spine
lack of physical activity
Other causes of sciatic nerve dysfunction include:
compression of the nerve by nearby bones, such as the vertebrae of the spine
damage from toxic agents, such as lead poisoning or alcoholism
decreased blood supply to the nerve
diabetic neuropathy, which is nerve damage caused by high blood glucose levels seen in some individuals with diabetes
surgery or other medical procedures that accidentally damage the nerve
trauma, such as a gunshot wound or hip fracture