Sciatica: Why Does Pain Travel Down Your Leg?

Have you ever experienced a sharp, burning pain that starts in your lower back and shoots all the way down your leg? Or perhaps you've noticed numbness, tingling, or weakness in one leg? If so, you may be experiencing sciatica.

Sciatica is one of the most common conditions we see at Zanx Physiotherapy & Rehab, and the good news is that most people improve without surgery when treated early and appropriately.

What Is Sciatica?

Sciatica is not a disease itself. It is a symptom caused by irritation or compression of the sciatic nerve, the largest nerve in the human body.

The sciatic nerve begins in your lower spine (L4-S3 nerve roots), passes through your buttock, and travels down the back of each leg to your foot.

When this nerve becomes irritated or compressed, pain follows the path of the nerve—this is why the discomfort often radiates from your back into your leg.

Why Does the Pain Travel Down the Leg?

Unlike muscle pain that stays in one location, nerve pain follows the course of the affected nerve.

Think of the sciatic nerve like an electrical cable.

If the cable is pinched near its starting point, the "signal" can be felt anywhere along the wire—even far away from where the compression actually occurs.

That's why someone with a problem in their lower back may feel pain in:

• The buttock

• Back of the thigh

• Calf

• Outside of the leg

• Foot

• Toes

Sometimes the leg pain is actually worse than the back pain.

Common Symptoms of Sciatica

Sciatica symptoms vary depending on how severely the nerve is irritated.

You may experience:

• Sharp or shooting pain

• Burning sensation

• Electric shock-like pain

• Tingling ("pins and needles")

• Numbness

• Muscle weakness

• Difficulty walking

• Pain when coughing or sneezing

• Pain after prolonged sitting

Most people experience symptoms on only one side.

What Causes Sciatica?

Several conditions can compress or irritate the sciatic nerve.

1. Lumbar Disc Herniation

This is the most common cause.

A bulging or slipped disc presses against a nearby nerve root, causing pain to radiate down the leg.

Common in:

• Adults aged 20–50

• People who frequently lift heavy objects

• Office workers who sit for long periods

2. Spinal Stenosis

As we age, the spinal canal can become narrower.

This narrowing compresses the nerves and may cause:

• Leg pain while walking

• Relief after sitting down

• Numbness

• Weakness

3. Piriformis Syndrome

The piriformis muscle sits deep in the buttock.

If this muscle becomes tight or inflamed, it can compress the sciatic nerve.

Pain often worsens after:

• Sitting

• Driving

• Climbing stairs

4. Degenerative Spine Changes

Arthritis and wear-and-tear changes may narrow the spaces where nerves exit the spine.

This can gradually lead to sciatica symptoms.

5. Spondylolisthesis

One vertebra slips forward over another, narrowing the space for the nerves.

Risk Factors

You are more likely to develop sciatica if you:

• Sit for long hours

• Lift heavy objects incorrectly

• Have poor posture

• Are overweight

• Smoke

• Have diabetes

• Lack regular exercise

• Have weak core muscles

How Is Sciatica Diagnosed?

A physiotherapist will assess:

• Your pain pattern

• Movement of your spine

• Muscle strength

• Reflexes

• Sensation

• Walking pattern

Special tests such as the Straight Leg Raise (SLR) or Slump Test may help identify nerve irritation.

If symptoms are severe or not improving, your doctor may recommend imaging such as an MRI to identify the cause.

Can Physiotherapy Help?

Absolutely.

Research consistently shows that physiotherapy is an effective first-line treatment for many people with sciatica.

Your treatment plan may include:

Pain Relief

• Manual therapy

• Joint mobilisation

• Soft tissue techniques

• Heat or cold therapy

• TENS (when appropriate)

Improve Movement

Your physiotherapist may prescribe exercises to:

• Restore spinal mobility

• Improve hip flexibility

• Reduce nerve irritation

• Correct movement patterns

Strengthening

Building strength in your:

• Core muscles

• Glutes

• Hip muscles

• Lower back

helps reduce stress on your spine.

Nerve Gliding Exercises

Special exercises encourage the sciatic nerve to move more freely and may reduce irritation.

Education

Learning:

• Correct lifting techniques

• Sitting posture

• Safe exercises

• Activity modification

helps prevent future flare-ups.

When Should You Seek Medical Attention Immediately?

Although uncommon, seek urgent medical care if you experience:

• Loss of bladder or bowel control

• Numbness around the groin or saddle area

• Severe weakness in the leg

• Difficulty walking that is rapidly worsening

• Sudden loss of sensation

These may indicate a serious condition requiring immediate treatment.

Can Sciatica Go Away?

Yes.

Many people recover within 6–12 weeks, especially with appropriate treatment and exercise.

However, ignoring symptoms or remaining inactive for prolonged periods may delay recovery and increase the risk of recurrence.

Tips to Prevent Sciatica

✔ Stay physically active

✔ Strengthen your core muscles

✔ Lift with your legs, not your back

✔ Avoid sitting for prolonged periods

✔ Maintain a healthy body weight

✔ Stretch regularly

✔ Improve your posture at work and home