The spine is divided into several sections. The cervical vertebrae make up the neck. The thoracic vertebrae comprise the chest section and have ribs attached. The lumbar vertebrae are the remaining vertebrae below the last thoracic bone and the top of the sacrum. The sacral vertebrae are caged within the bones of the pelvis, and the coccyx represents the terminal vertebrae or vestigial tail.

The main nerve traveling down the leg is the sciatic nerve. Pain associated with the sciatic nerve usually originates higher along the spinal cord when nerve roots become compressed or damaged from narrowing of the vertebral column or from a slipped disk. Symptoms can include tingling, numbness, or pain, which radiates to the buttocks legs and feet.

Herniated nucleus pulposus is a condition in which part or all of the soft, gelatinous central portion of an intervertebral disk is forced through a weakened part of the disk, resulting in back pain and nerve root irritation.

When the soft, gelatinous central portion of an intervertebral disk is forced through a weakened part of a disk, it is a condition known as a slipped disk. Most herniation takes place in the lumbar area of the spine, and it is one of the most common causes of lower back pain. The mainstay of treatment for herniated disks is an initial period of rest with pain and anti-inflammatory medications followed by physical therapy. If pain and symptoms persist, surgery to remove the herniated portion of the intervertebral disk is recommended.

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