Sciatica

General Information

Sciatica is a clinical diagnosis resulting from nerve compression, or a pinched nerve, in the lumbar spine causing severe pain, numbness, and even weakness in the lower extremity.

The sciatic nerve is a large neurological structure that is actually the size of three finger breaths and is located outside of the spine. It is made up of at least four spinal nerves after they exit the spine through the foraminal canals between each vertebra. The actual sciatic nerve is located behind the buttocks and extends down the back side of the thigh, branches out like the limbs of a tree, and supplies the lower leg from the knee down.

The symptoms of sciatica will depend on which of the spinal nerves that make up the sciatic nerve is being compressed or pinched (e.g., L4, L5, S1, or S2). A herniated disc is the most common cause of sciatica and the two are often used interchangeably. Sciatica can also be caused by compression of the sciatic nerve outside of the spine in the buttocks area – the most common called a pyriformis muscle syndrome.