The sural nerve is one of the cutaneous sensory nerves of the leg and foot. It plays a significant role in the lower limb by providing sensory information to the brain about the condition of the calf and lateral foot tissues.
Anatomy
The sural nerve arises from the fusion of the medial sural cutaneous nerve and the peroneal anastomotic branch of the lateral sural cutaneous nerve. From its origin, it descends along the leg and foot, following alongside the lesser saphenous vein of the leg. The sural nerve passes through the calf (sural region) superficial to the gastrocnemius muscle and lateral to the calcaneal (Achilles) tendon. As it crosses the ankle joint, it passes posterior to the lateral malleolus and turns to run along the lateral side of the foot. Along its path, the sural nerve forms many smaller branches that innervate the skin and supporting tissues of the lower calf, ankle, and lateral foot.
Physiology
The sural nerve plays an important role in the nervous system of the calf, ankle, and foot. It is a sensory nerve that carries afferent signals from the skin in these regions back to the spinal cord and brain. Sensory information about touch, pressure, and pain allows the brain to perceive objects touching the ankle and foot and avoid potentially dangerous injuries.