Spinal Stenosis: When Narrowing of the Spine Causes Nerve Pressure

If you feel pain, numbness, or weakness in your legs when standing or walking but relief when sitting or leaning forward you may have Spinal Stenosis.

This condition occurs when the spinal canal or nerve passageways become too narrow, putting pressure on the spinal cord or nerves. It’s one of the most common causes of leg pain in older adults.

What Is Spinal Stenosis?

The spinal canal is a tunnel that houses the spinal cord and nerve roots. Stenosis means “narrowing.” When this space becomes restricted, the nerves that travel through it can become compressed or irritated, leading to pain and weakness.

There are two main types:

Central canal stenosis

narrowing around the spinal cord or nerve roots.

Foraminal stenosis

narrowing of the small openings where nerves exit the spine.

What Causes Spinal Stenosis

• Arthritis and bone spurs (from lumbar spondylosis)

• Thickened ligaments that encroach on the canal

• Bulging or herniated discs pressing on nerves

• Spondylolisthesis (vertebra slipping forward)

• Congenital narrowing (present from birth)

• Post-surgical changes or scar tissue

Common Symptoms

Spinal stenosis often develops gradually.

Typical signs include:

• Pain or cramping in the legs when standing or walking

• Relief when sitting, leaning forward, or pushing a cart (“shopping cart sign”)

• Numbness or tingling in the buttocks, legs, or feet

• Leg weakness or heaviness after short distances

• Back pain that may be mild or absent

How It’s Diagnosed

Medical History and Physical Exam

Your physician evaluates symptom patterns, walking tolerance, and neurological function. Flexion or extension testing often reproduces symptoms.

Imaging

• MRI: the gold standard for showing nerve compression and canal narrowing.

• CT Myelogram: used when MRI isn’t possible or to detail bony anatomy.

• X-rays: assess alignment, arthritis, or vertebral slippage.

Diagnostic Injections

Image-guided nerve root blocks can help identify which level is responsible for pain.

Typical Patterns of Pain

Lumbar spinal stenosis most often affects the L4–L5 and L5–S1 levels.

Cervical stenosis affects the neck, arms, and hands, while thoracic stenosis is rare.

Patients often report:

• Pain when upright or walking

• Relief when sitting, bending forward, or lying flat

• Fatigue or weakness after standing for long periods

Risk Factors

• Adults over age 50

• Those with arthritis or prior back injury

• People with physically demanding jobs

• Individuals with scoliosis or spinal deformity

• Patients with prior spine surgery

Who Is at Risk

• Age between 30 and 60

• Sedentary lifestyle or prolonged sitting

• Obesity or heavy lifting

• Smoking (reduces disc nutrition)

• Prior disc injury or degeneration

When to See a Specialist

If standing or walking causes leg pain, numbness, or weakness—but sitting relieves it—you may have nerve compression from spinal stenosis.

A specialist can identify the affected area and recommend the most effective path forward.