The question of whether arthritis pain can radiate down the leg has a specific answer: Yes, but only when the condition affects the spine. Common forms of arthritis, such as osteoarthritis in the knee or hip, typically cause localized pain, stiffness, and aching near the joint itself. However, when arthritis involves the small joints of the vertebrae in the lower back—often called spinal arthritis or spondylosis—it interferes with the nerves traveling from the spinal cord to the legs. This interference leads to radiculopathy, which is the true cause of radiating leg pain.
The Spinal Connection: How Arthritis Leads to Radiating Pain
The mechanism by which spinal arthritis causes pain to travel down the leg begins with the degeneration of structures within the lower back, or lumbar spine. Osteoarthritis causes the protective cartilage cushioning the facet joints—the small joints connecting the vertebrae—to wear down over time. As this cartilage deteriorates, the body generates extra bone tissue, resulting in the formation of bone spurs, or osteophytes.
These bony growths, along with the thickening of spinal ligaments and bulging intervertebral discs, encroach upon the limited space available for the spinal nerves. When these passages become restricted, the condition is called spinal stenosis or foraminal stenosis. This narrowing physically pinches the nerve root as it exits the spine, a process known as nerve root compression.
The compression of a nerve root in the lumbar spine causes a referred pain that travels along the nerve’s pathway into the leg, a phenomenon termed lumbar radiculopathy. When the compression involves the nerve roots that form the large sciatic nerve, the resulting discomfort is commonly referred to as sciatica. This pain is felt far from its origin point in the spine, tracing a path down the buttocks, thigh, and sometimes into the calf and foot.
In contrast, arthritis in a major lower limb joint like the hip or knee rarely produces true radiating pain. Hip arthritis pain is usually felt in the groin or the front of the thigh, and while it can sometimes be referred to the knee, it does not extend below the knee or present with the electrical quality of nerve pain. The distinct difference lies in the direct contact with the spinal nerve roots, which is unique to arthritic changes in the lumbar spine.
Recognizing the Symptoms of Arthritic Nerve Pain
The pain that radiates from arthritic nerve compression has distinct characteristics that differentiate it from localized joint aching. Patients often describe the sensation as sharp, burning, or an electric shock, contrasting with the dull, deep ache typical of a damaged joint. This discomfort frequently starts in the lower back or buttock area and shoots down one leg, following the specific distribution of the affected nerve root, known as a dermatome.
Nerve compression from spinal arthritis often produces sensory symptoms collectively known as paresthesia. These can include tingling, a feeling of “pins and needles,” or numbness in parts of the leg or foot. The specific location of the numbness or tingling helps physicians pinpoint exactly which lumbar nerve root is being compressed by the arthritic changes.
Motor symptoms may also occur if the compression is severe enough to affect the nerve’s ability to signal muscles. This manifests as muscle weakness in the foot or leg, which can lead to difficulty lifting the front part of the foot, commonly called “foot drop.” Symptoms are often exacerbated by activities that increase pressure on the spine, such as standing, walking, coughing, or sneezing.
A defining feature of nerve pain caused by spinal stenosis is its relief when the patient changes position. Pain and weakness that increase with standing or walking but improve when sitting down or bending forward—a posture that temporarily opens the spinal canal—is highly suggestive of nerve compression. This positional response helps distinguish arthritic nerve pain from issues caused by blood vessel restriction.
Seeking Professional Diagnosis
If you experience pain that radiates down your leg with an electrical quality, or if it is accompanied by numbness or weakness, seek medical evaluation. The diagnostic process for arthritic nerve pain, or radiculopathy, begins with a thorough physical examination to test reflexes, sensation, and muscle strength in the legs. These tests help the physician determine which specific nerve is involved and the severity of the compression.
Imaging studies are necessary to confirm the diagnosis and visualize the structural changes in the spine. X-rays can reveal the presence of bone spurs and the degree of joint space narrowing, while a Magnetic Resonance Imaging (MRI) scan provides the most detailed view of the soft tissues. MRI is particularly effective at showing compressed nerve roots, bulging discs, and the extent of spinal stenosis caused by arthritis.
A doctor may order nerve conduction studies or an electromyogram (EMG) to assess the electrical activity of the nerves and muscles. These tests help confirm nerve damage and rule out other causes of leg pain, like disc herniation or peripheral nerve conditions. Seek immediate medical attention if radiating leg pain is accompanied by new-onset bowel or bladder dysfunction, as this indicates a severe condition requiring urgent intervention.