What Is Sciatica?
You may have been diagnosed with sciatica, or you may suspect that you have it. Either way, the name of the condition is intimidating, and so is the pain. This post will explain what sciatica is, discuss its symptoms, and describe possible causes. Sciatica is an irritation or compression of the sciatic nerve. To understand how and why this condition occurs, it is first necessary to learn the very basic anatomy of the spine. The spinal area includes: the spinal cord, made up of nerves; the vertebrae; the inter-vertebral discs; the muscles; the tendons; the ligaments; and the connective tissues.
Nerves allow communication throughout the body. The bundle of nerves that make up the spinal cord travels from the brain through the entire length of the spinal canal, and small groups of these nerves branch off to various parts of the body. The vertebrae are an interlocking series of nearly circular-shaped bones of differing sizes. Each vertebra has a hole in the middle through which the spinal cord runs.
Spinal Anatomy and How It Affects the Sciatica
There are twenty-four vertebrae, divided into three sections: the seven cervical vertebrae; the twelve thoracic vertebrae; and the five lumbar vertebrae. These bones provide support and protection for the spinal cord, and allow the back to twist and move in numerous ways. The inter-vertebral discs, composed of cartilage, separate the vertebrae and cushion them during movement. At the end of the spinal cord is the sacrum, which is a triangular-shaped bone plate formed from five fused vertebrae, and finally the tiny coccyx, also a triangular-shaped bone, formed from several rudimentary vertebrae. The muscles in the back support the spine in an upright position and also allow the back to rotate, twist, bend, and maintain proper spinal curves.
Tendons connect muscles to bones, allowing the contracted muscles to move the bones smoothly. Ligaments connect bones to bones, providing support and proper movement of joints. Finally, the connective tissue supports, binds, and connects body structures. Obviously, when healthy, all of these components work together to allow you easy movement and considerable flexibility.
When viewing a person’s spine from the back of the body, the vertebrae appear to form a straight column of interlocking bones. But the view from the side of the body, as depicted, reveals three natural, spinal curves:
- One in the neck
- Another in the upper back
- Third in the lower back region.
This, of course, does not include the very end of the spinal column; there are natural curves in the coccyx
These three curves indicate a flexible structure with the ability for give and take. All components of the spine and back rely on each other for the entire spinal system to function properly. A problem in one area can have a consequent negative impact on another.
Causes of Sciatica Pain
The sciatic nerve is formed from several spinal nerves that pass through the openings in the sacrum—as mentioned previously, the lower portion of the spine. This nerve is the primary nerve in the leg, and the longest and largest nerve in the body. Its pathway originates in the lower back, passes through the deep layers of the buttock muscle, to the back of the thigh, where slightly above the knee it divides into two large branches.
The shorter branch of the nerve turns toward the outer edge of the leg and ends just below the kneecap, and the longer branch extends down the back of the leg to the heel area. When this nerve is pressed or irritated, a sharp, electrical wave of pain, along with other symptoms, such as numbness, tingling, weakness, achiness, and burning, can occur anywhere along the pathway. This is sciatica.
Sciatica is a symptom of and a frequent companion to lower back pain. It can also can be a separate problem in and of itself, with its own symptoms. Although incorrectly thought of as a disease or illness, sciatica is an inflammatory condition caused, as mentioned above, by irritation or compression of the sciatic nerve. It can be due to a number of possible causes. To relieve the symptoms of sciatica many people use Inversion Therapy.