The sural nerve, also known as the short saphenous nerve, runs the length of the lower calf in a person's leg and down into the foot and toes. It refers to a group of nerves that branch out through the leg and control impulses sent from the foot up through the knee and to the central nervous system (CNS). The CNS is part of the nervous system crucial to sending and receiving messages between the brain and the leg, foot, and toes so a person can walk and react to pain properly. Injuries to this nerve, or set of nerves, result in pain, tingling, or numbness.
Following the sural nerves in the body starts at the knee. Here, the tibial nerve turns into the medial sural cutaneous nerve. Like a network of roads changing names as they cross other roads or stretch across a city, the sural nerves branch out and undertake several name changes as they travel throughout the leg.
While the medial sural cutaneous nerve descends into the center of the leg, the lateral sural cutaneous nerve covers the surface areas of the leg to receive messages from the skin. The main sural nerve runs near the small saphenous vein and down to the foot. The small saphenous vein supplies blood flow to major areas of the leg. The sural nerve sends messages along this long highway of nerves to keep the foot and leg functioning properly.
When a severe injury to a nerve does occur, it may require grafting to fix. This process involves taking a small section of a healthy nerve and attaching it to the dysfunctional nerve. Approximately 7 to 9 inches (20 to 25 cm) of the sural nerve can be used in a nerve graft operation to repair other nerves in the area.
Pain or injury to the foot or leg can cause damage or discomfort to the sural nerve or a related nerve in its network. A patient with this type of injury may experience involuntary spasms and feel pain or an unpleasant tingling sensation in the injured area. Since nerves transmit messages throughout the entire system, the pain may not be located at the actual site of the injury. The sural nerves can transfer pain from an injury in any area from the knee down, including the foot.