Lumbar Radiculopathy (Pinched Nerve in the Lower Back)

What lumbar radiculopathy is

The spinal cord ends around the first lumbar vertebra. Below that, nerve roots run down the spinal canal and exit through openings called foramina at each level. Each root supplies sensation to a strip of skin (a dermatome) and power to particular muscles (a myotome).

"Radiculopathy" means a problem with a nerve root. When a root is squeezed or chemically inflamed, for example by material leaking from a disc, it sends pain and abnormal sensations along its whole territory. That is why a problem in the back is felt mainly in the leg.

Sciatica is the everyday name for radiculopathy of the L4, L5 or S1 roots, which form the sciatic nerve. Our sciatica page covers that pattern in depth. Radiculopathy of the higher lumbar roots (L2 to L4) causes pain in the front of the thigh instead. See radiculopathy for neck and mid-back types.

Symptoms by nerve root

Common features

• Leg pain worse than back pain, often sharp, burning or electric
• Pain worsened by sitting, coughing, sneezing or straining (disc causes)
• Numbness, tingling or pins and needles in a stripe matching the root
• Weakness in the muscles of that root
• With spinal stenosis: leg heaviness, pain or numbness brought on by walking or standing and relieved by sitting or bending forward (neurogenic claudication)

Causes

• Herniated disc: the most common cause in adults aged 30 to 50. Disc material presses on and inflames the root, usually at L4-L5 (L5 root) or L5-S1 (S1 root).
• Spinal stenosis: narrowing of the canal or foramina from arthritis, thickened ligaments and disc bulging. Most common after 60.
• Spondylolisthesis: one vertebra slipping forward on another, narrowing the foramen.
• Degenerative disc disease and bone spurs (osteophytes).
• Facet joint cysts.
• Less common: spinal tumors, infection (epidural abscess), fractures, diabetes-related nerve root damage, and shingles affecting a lumbar root.

Conditions that mimic radiculopathy

• Piriformis syndrome: buttock pain from irritation of the sciatic nerve by the piriformis muscle
• Hip arthritis and trochanteric bursitis (outer hip pain)
• Peripheral neuropathy (both feet, glove-and-stocking pattern)
• Meralgia paresthetica (burning numbness on the outer thigh, no weakness)
• Peripheral artery disease (calf pain when walking, eased by standing still)

How it is diagnosed

Examination

• Straight leg raise: lifting the straight leg while you lie on your back reproduces leg pain below the knee between about 30 and 70 degrees in L5 or S1 radiculopathy.
• Femoral stretch test: lying face down, bending the knee reproduces front-of-thigh pain in L2 to L4 radiculopathy.
• Testing of sensation, muscle strength and reflexes to pinpoint the root.

Tests

• MRI is the best test. It is recommended urgently for red flags, or when symptoms persist beyond 6 to 8 weeks and injection or surgery is being considered. Disc bulges on MRI are common in people without symptoms, so findings must match the exam.
• CT myelogram if MRI is not possible.
• Electromyography (EMG) and nerve conduction studies help when the diagnosis is uncertain, for example to distinguish radiculopathy from peripheral nerve problems.
• Blood tests if infection or cancer is suspected.

Treatment

First 6 weeks

Most radiculopathy from a disc herniation improves on its own as the disc material shrinks and inflammation settles.

• Stay as active as you can. Bed rest does not speed recovery.
• Heat and position changes.
• NSAIDs such as ibuprofen or naproxen at the label dose, if safe for you (avoid with kidney disease, stomach ulcers or some heart conditions). Acetaminophen (paracetamol) can be added.
• Physical therapy: directional exercises, nerve gliding, core strengthening and graded return to activity.
• Medicines for nerve pain, such as gabapentin or pregabalin, have shown limited benefit for sciatica in trials. Short courses of oral steroids give modest short-term relief. Opioids are generally avoided.

Epidural steroid injection

An image-guided injection of steroid near the affected root can reduce leg pain for weeks to months. It does not change the long-term outcome but can help you stay active and avoid or delay surgery.

Surgery

Surgery is considered for:

• cauda equina syndrome or progressive weakness (urgent)
• disabling leg pain that persists beyond about 6 to 12 weeks despite good non-surgical care

Options include microdiscectomy for disc herniation, and decompression (laminectomy or foraminotomy), sometimes with fusion, for stenosis or spondylolisthesis. Surgery relieves leg pain faster than non-surgical care, though results at 1 to 2 years are often similar for disc herniation.

Outlook

About 3 in 4 people with acute lumbar radiculopathy from a disc herniation improve substantially within 3 months. Numbness may take longer to resolve than pain, and some mild numbness can persist. Recurrence occurs in a minority. Stenosis-related symptoms tend to be longer lasting and fluctuate.

Frequently asked questions

What is the difference between lumbar radiculopathy and sciatica?

Lumbar radiculopathy is any nerve root problem in the lower back. Sciatica is the common name for radiculopathy of the L4, L5 or S1 roots, which form the sciatic nerve, causing pain down the back or side of the leg. Upper lumbar radiculopathy causes front-of-thigh pain instead.

What are the symptoms of L5 radiculopathy?

Pain runs down the outer thigh and shin to the top of the foot and big toe, with numbness in the same area. Weakness lifting the big toe or foot can cause foot drop, so the toes catch when walking. Reflexes are usually normal.

How long does lumbar radiculopathy take to heal?

Most people improve significantly within 6 to 12 weeks, and about three-quarters are much better by 3 months. Numbness and mild weakness may take several months to recover. Persistent or worsening symptoms after this time should be reassessed, often with an MRI.

When is surgery needed for a pinched nerve in the lower back?

Urgent surgery is needed for cauda equina syndrome or progressive weakness. Otherwise, surgery is an option when severe leg pain persists beyond about 6 to 12 weeks despite non-surgical treatment and the MRI matches the symptoms. Microdiscectomy is the most common operation.

What should I avoid with lumbar radiculopathy?

Avoid prolonged sitting, heavy lifting with a bent and twisted back, and long periods of bed rest. Movement, walking and gentle exercises usually help more than resting. Stop any activity that makes leg pain spread further down the leg, and discuss exercises with a physical therapist.