Why Does My Back Hurt When I Sit?

Lower back pain when sitting is one of the most common reasons people contact a physiotherapist. Whether it comes on after long days at a desk, driving, or relaxing on the sofa, it can be frustrating — and worrying.

The good news? In most cases, it’s treatable and not serious.

Below, we’ll explain the most common causes, what you can do about it, and when physiotherapy can help.

Common causes of lower back pain when sitting

1. Prolonged static posture

Your spine loves movement! Movement encourages blood flow, reduces inflammation and triggers joint lubrication via the synovial membrane (a membrane that surrounds each joint).

Over time, this can lead to:

• Muscle pains and spasms

• Joint irritation

• Reduced movement in the spine

Even “good posture” held too long can cause pain — movement matters more than perfection.

2. Muscle weakness

Tight hip flexors, hamstrings, or lower back muscles have commonly been named as causes of back pain. The reality is, weakness plays a much larger factor here.

Weak lower back muscles for example the paraspinals means that they are working to their limit even during day to day tasks, leading to fatigue and pain — especially by the end of the day.

3. Disc-related irritation

The most common causes of disc related issues are related to one of 3 main causes; genetics, being over weight and smoking. Unfortunately sitting longer periods when you have a disc issue is almost certainly going to negatively impact your lower back. As mentioned in part one, the spine, including the discs respond well to movement even though the main cause may not be sitting, you may experience:

• Pain that worsens the longer you sit

• Relief when standing or walking

• Occasional stiffness or sharp discomfort

This doesn’t necessarily mean a “slipped disc” — most disc-related pain settles well with the right treatment and advice.

4. Stress and tension

Stress often shows up physically. Increased muscle tension, shallow breathing, and reduced movement can all contribute to lower back pain — particularly in desk-based roles.

Should I be worried?

Most lower back pain:

• Is not serious

• Improves with movement

• Responds well to mixed exercise and hands on physiotherapy approach

You should seek professional advice if you have:

• Constant unremitting pain

• Pain worsening over time

• Pain effecting quality of life

• Pain affecting sleep or daily activities

• Numbness or tingling in the legs

Any issues with bladder or bowel function, saddle area numbness, sexual dysfunction or limb weakness for example foot drop you should attend your local emergency unit or speak with a professional ASAP.

What can I do to help my back when sitting?

Here are a few simple tips that often help:

• Change position regularly (every 20 minutes minutes)

• Use a chair with good lower back support that is comfortable

• Keep feet flat on the floor

• Do chair based stretches if no time to get up and move around

• Add gentle movement breaks during the day

• Back strengthening exercises daily to help counter the weakening effects of sitting.

If pain persists, exercises and advice should be tailored to you — generic stretches don’t work for everyone.

How physiotherapy can help

Physiotherapy looks beyond just where it hurts.

At DCM Physiotherapy, treatment for lower back pain typically includes:

• A thorough assessment to identify the cause

• Hands-on treatment

• Personalised exercises to improve strength and mobility

• Advice on sitting, work setup, and daily habits

• A clear plan to get you back to normal activities confidently

The goal isn’t just pain relief — it’s preventing the problem from returning.

When should I book an appointment?

If sitting is:

• Affecting your work

• Limiting your comfort

• Stopping you from exercising or relaxing

…it’s a good idea to get it checked.

Early physiotherapy often means faster recovery and fewer flare-ups.

Need help with lower back pain?

If you’re struggling with back pain when sitting and you’re based locally, or would like a virtual appointment we’re here to help.

👉 Book an appointment with DCM Physiotherapy today and get clear answers, expert treatment, and a plan that works for you.