Why Does My Lower Back Hurt When I Sit? 7 Common Reasons

If your lower back hurts when you sit, you’re not alone. Sitting is one of the most common triggers for lower back pain we see, whether it’s long hours at a desk, a drive across Southwest Florida or a flight to visit family.

The good news is that sitting pain is usually very fixable. Below are the most common reasons your back hurts when you sit, simple changes you can make today, and when it’s time to get it checked.

Why Sitting Is Hard on Your Lower Back

Your body isn’t designed to stay in one position for hours. Sitting, especially slouched, puts more pressure on the discs (the shock absorbers between your vertebrae) and the ligaments of your lower back. When you add weak core muscles or stiff hips, that pressure builds into pain.

7 Reasons Your Lower Back Hurts When You Sit

1. Poor Posture

Slouching or hunching strains the muscles and ligaments of your back. Looking down at a screen or phone tips your head forward and adds strain to your neck and upper back too.

Try this: sit back against the backrest so your lower back muscles can relax. When you perch on the edge of the seat, your back and hip flexor (psoas) muscles have to work the whole time, which increases compression on the spine. Aim to keep your lower back’s natural curve, without rounding or over-arching.

2. Weak Core Muscles

Your abdominal and back muscles support your spine. If they’re weak, your back takes more of the load. Many people with sitting pain sit with their pelvis tucked under (a posterior pelvic tilt), which rounds the spine and stresses the ligaments over time.

3. Sitting Too Long

Long periods of sitting make muscles stiff and joints less mobile. Try this: get up and move every 30 minutes, even for a minute or two.

4. Not Enough Activity

An inactive lifestyle leaves muscles weak and stiff. Aim for about 30 minutes of moderate activity a day, like a brisk walk or light strength training. If you have a desk job, consider a standing desk or regular movement breaks.

5. Muscle Imbalances

When some muscles are much stronger or tighter than others, your body shifts its load in unhealthy ways. A balanced routine that works different muscle groups helps.

6. A Disc Problem

Sitting puts the most pressure on the discs. A herniated or bulging disc often hurts more with sitting and bending, and can cause pain, tingling or numbness down the leg. The McKenzie Method is one approach that often helps. Read more about herniated discs and lower back pain.

7. The Wrong Chair or Couch

A soft couch or a chair without support makes it hard to sit well. Keep your feet flat on the floor, knees at about 90 degrees, and your screen at a comfortable height. A lumbar cushion, or even a rolled towel behind your lower back, can make a big difference.

Other Conditions That Can Make Sitting Painful

• Muscle strain: overstretching or twisting the back. Pain may spread into the buttock but not the leg. Most strains settle within about a month, but poor sitting habits can keep them going.
• Sciatica: irritation of the sciatic nerve, often on one side, which long periods of sitting can make worse. Some conditions only mimic it; see three conditions that mimic sciatica.
• Degenerative disc changes: discs dry out with age and can cause back pain and sciatica-like symptoms.
• Spinal stenosis: narrowing around the nerves, from bone spurs or disc changes with age.

Don’t Rest an Achy Back for Too Long

Lying down for days usually makes back pain worse, not better. Gentle movement, short walks and the right exercises help your back recover faster.

When to See a Doctor Right Away

• Loss of bladder or bowel control, or numbness in the groin
• Leg weakness that’s getting worse
• Back pain with fever or unexplained weight loss
• Severe pain after a fall or accident

How We Help

At our clinics in Fort Myers, Cape Coral and Estero, a Doctor of Physical Therapy will find out why sitting hurts. That could be your posture, your core, your hips or a disc. Then we build a plan to fix it, including how you sit at work and at home. Learn more about our back pain relief program, and read common causes of lower back pain.

Frequently Asked Questions

Why does my lower back hurt when I sit but not when I stand?

Sitting puts more pressure on the discs and stretches the ligaments when you slouch. Disc irritation and weak core support are the most common reasons.

What is the best sitting position for lower back pain?

Sit back against the chair with your lower back supported, feet flat and knees at about 90 degrees, and get up to move every 30 minutes.

Can physical therapy fix back pain from sitting?

Yes. Once we know the cause, the right exercises and posture changes usually make a big difference.

Sit Comfortably Again

Start with our Fixing the Cause & Not Just the Symptoms Assessment, or Inquire About an Appointment →

Call our office at (239) 223-0484 to schedule your appointment.