A lumbar nerve is part of the cable-like network of fibers which transmits sensations and movement between the brain and the body. In the human body, five lumbar nerves are grouped together in a set known as the lumbar plexus. Lumbar nerves are part of the peripheral nervous system which springs out of the vertebrae or spinal bones in the lumbar or low back. These fibers connect and act upon the low back, trunk, legs and feet.
Nerves, the main component of the nervous system, are the corded trails through the body which carry information using electrical signals. These impulses originate in the brain and spinal cord. The sensation, positioning and movement of a body part are all controlled through the communication path of a nerve.
The first lumbar nerve begins at the level of the last thoracic, or trunk, and the first lumbar, or low back, spinal bones. Each nerve is divided into a front or anterior section and a back or posterior section. This positioning determines the area to which the nerve sends signals. The lumbar nerve known as the obturator nerve, for example, stems from the second to the fourth bones of the lumbar area and acts as a pathway to the hip, thigh and knee. The sciatic nerve originates on the third spinal bone and transmits signals from the low back, down the back of the leg to the foot.
Irritation of a lumbar nerve can occur when the body calls upon the inflammation process due to an injury. This can create abnormal pressure on a nerve or group of nerves, causing it to become compressed or trapped. When a lumbar nerve is squeezed it can produce symptoms varying from a stinging or tingling feeling to difficulty with movement.
Excessive stress placed on the sciatic nerve can trigger problems in the low back which travel the entire length of the nerve. Called sciatica, symptoms can range from localized low back pain to pain radiating into the thigh or calf. Severe entrapment may also result in a failure to control the bladder or an inability to point the toes upward.
When pain or other problems result from lumbar nerve restriction it is important to minimize the inflammation or swelling and open up the constraints pushing against the nerve fibers. Initial swelling after an injury is commonly treated with the application of ice and a brief period of rest. Once swelling dissipates, stretching of the muscles, tendons and ligaments surrounding the lumbar nerve may ease the abnormal pressure and spring the nerve from its confinement.