The sciatic nerve can be a source of calf pain. Originating in the lower back, this nerve plays a significant role in leg sensation and movement.
The Sciatic Nerve and Its Reach
The sciatic nerve forms from five nerve roots in the lower spine, specifically from the L4 to S3 segments. These roots merge deep in the buttock, near the piriformis muscle, to form a single, thick nerve. From there, it extends down the back of the thigh, through the gluteal region and behind the hamstring muscles.
Near the back of the knee, the sciatic nerve divides into two main branches: the tibial nerve and the common fibular (peroneal) nerve. The tibial nerve continues down the back of the calf to the heel and sole of the foot, while the common fibular nerve travels along the outer lower leg. These branches provide sensation to the skin of the calf and foot, and enable movement in the leg and foot muscles. When the sciatic nerve or its roots are compressed or irritated (radiculopathy), pain can radiate along its pathway, including into the calf.
Recognizing Sciatica
Sciatica describes pain following the path of the sciatic nerve, often stemming from irritation of nerve roots in the lower back. Pain typically presents as a sharp, shooting, or burning sensation traveling from the lower back or buttock down one leg. While it frequently affects the buttock and the back of the thigh, it commonly extends into the calf and sometimes even to the foot and toes.
Alongside pain, individuals might experience tingling (“pins and needles”) or numbness in the affected leg or foot. Muscle weakness in the leg can also occur. Symptoms can vary from a mild ache to severe pain, and may worsen with movements like sitting for extended periods, coughing, or sneezing. It is common for sciatica to affect only one side of the body.
Common Triggers of Sciatic Pain
Sciatic pain arises when something impinges upon or irritates the sciatic nerve or its roots in the lower back. A common cause is a herniated disc, where the inner material of a spinal disc presses on a nearby nerve root.
Spinal stenosis, a narrowing of the spinal canal, can also put pressure on the nerve roots that form the sciatic nerve. Spondylolisthesis, where one vertebra slips forward over another, can also impinge on the nerve. Piriformis syndrome, a neuromuscular disorder, can also cause sciatica-like symptoms when the piriformis muscle compresses the sciatic nerve.
When to Seek Professional Guidance
While mild sciatic pain often improves with self-care, consulting a healthcare professional for diagnosis and management is advisable. An evaluation can help determine the underlying cause and differentiate sciatica from other conditions causing calf pain.
Immediate medical attention is necessary for severe or worsening pain, or new symptoms. These include sudden numbness or muscle weakness in the leg, or loss of bladder or bowel control.