Lower Back Pain When Sitting: Causes, What Helps and When to See a Physio
Introduction
If your lower back starts to ache after an hour at your desk, a long drive or an evening on the sofa, you are far from alone. Lower back pain when sitting is a common reason people seek physiotherapy, particularly when symptoms begin affecting work, driving or everyday activities.
The good news is that most episodes of lower back pain are not caused by a serious medical problem and often improve with time, movement and appropriate self-management. That means it comes from how your spine, muscles and joints are loaded, not from serious damage. With the right changes and, where needed, the right treatment, it usually settles well.
In this guide, our physiotherapists explain why your lower back hurts when sitting, what you can do about it at home, and the clear signs that it is time to book a physio assessment.
Why Does My Lower Back Hurt When Sitting?
It seems odd that resting in a chair can hurt more than walking around. Yet Sitting changes how load is distributed through the lower back, hips and surrounding muscles. For some people, holding the same sitting position for a long time can aggravate sensitive tissues and increase stiffness or discomfort.
When you stand, your lower spine has a gentle inward curve that spreads load evenly across your discs, joints and muscles. When you sit, especially in a soft or low seat, your pelvis tends to roll backwards. Your spinal position changes when you sit, particularly in a low or unsupported chair. If that position is maintained for a long time, it may become uncomfortable, especially if your back is already sensitive.
Hold that position for a long time and three things happen:
- Tissues get tired. Muscles that hold you upright, such as the deep core and back extensors, fatigue and start to ache.
- Joints and discs stiffen. Spinal structures rely on movement to stay healthy and well nourished. Staying still for hours leaves them stiff and sensitive.
- Hips tighten. Long periods with your hips bent shorten the hip flexors at the front, which can pull on the lower spine when you finally stand up.
This is why many people notice lower back pain after sitting, not just during it. The first few steps after getting out of the car or up from a desk can feel stiff and sore until the back loosens up.
The key message is that your back is not designed for stillness. Back pain from sitting too long is usually your body asking you to move more, rather than a sign of damage.
Common Causes of Lower Back Pain From Sitting
Back pain when sitting rarely has a single cause. In our clinic, it is usually a mix of the factors below.
1. Slumped or poor sitting posture
Slouching rounds the lower back and shifts load onto the discs and ligaments. Perching forward on the edge of a seat or leaning to one side can be just as unhelpful. No single posture is perfect, but any posture held for too long becomes a problem.
2. Prolonged sitting without breaks
Desk jobs, commuting and long evenings in front of a screen can add up to eight to ten hours of sitting a day. Even a well-designed chair will not protect you if you rarely get up.
3. Muscle strain and weak core muscles
A sudden twist, heavy lift or awkward movement can strain the muscles of the lower back. Sitting then aggravates the irritated tissue. Weak deep abdominal and glute muscles also mean your spine has less support, so it tires faster.
4. Disc irritation or a bulging disc
The discs between your vertebrae act as shock absorbers. Sitting increases pressure on them, so if a disc is irritated or bulging, pain often feels worse in a chair and better when standing or walking. This is one of the classic patterns of lower back pain when sitting.
5. Sciatica and nerve irritation
If a disc or stiff joint irritates a nerve root, you may feel pain, tingling or numbness spreading into the buttock and down the leg. Sitting on hard surfaces or for long drives often makes it worse. Find out more about our sciatica treatment in Hastings.
6. Tight hip flexors and hamstrings
Tight muscles around the hips and back of the thighs change how the pelvis sits in a chair. This often leads to a flattened lower back and extra strain on the spine.
7. Facet joint and sacroiliac (SI) joint problems
The small facet joints of the spine and the SI joints where your spine meets the pelvis can become stiff or irritated. SI joint pain often feels like a deep ache on one side of the lower back, especially when sitting on one buttock or crossing your legs.
8. Arthritis and age-related changes
Wear and tear in the spine is normal as we get older and is not always painful. When it is, stiffness after sitting is a common feature. Physiotherapy plays a big part in arthritis management by keeping joints moving and muscles strong.
9. Stress and lifestyle factors
Poor sleep, stress, low activity levels and general fitness all affect how sensitive your back is to pain. Pain is not only about tissue, and a good physio will look at the whole picture.
What Helps Lower Back Pain When Sitting?
Most people can make a real difference with a few simple changes. Start with these.
Follow the 30-minute rule
The best posture is your next posture. Aim to stand up, walk or change position at least every 30 minutes. Set a reminder on your phone, take calls standing, or walk to the kettle or printer. Small, frequent breaks beat one long walk at lunchtime.
Set up your chair and desk properly
- Sit with your bottom right to the back of the chair so the backrest supports your lower back.
- Use a small cushion or rolled towel in the curve of your lower back if your chair lacks lumbar support.
- Keep your feet flat on the floor or on a footrest, with knees roughly level with or slightly below your hips.
- Position your screen at eye level and about an arm’s length away, so you are not craning forward.
- Keep your keyboard and mouse close, with elbows relaxed by your sides.
Adjust your car seat
For long drives, sit fairly upright, bring the seat close enough that you do not stretch for the pedals, and use the lumbar support. Stop every hour or so for a short walk.
Avoid soft, low sofas
Deep sofas tip your pelvis backwards and round your spine. A firmer, higher seat with a cushion behind your lower back is usually kinder.
Try gentle exercises and stretches
These simple movements can ease stiffness. Move slowly and stop if any exercise sharply increases your pain.
- Seated pelvic tilts: Sit tall and gently roll your pelvis forwards to arch your lower back, then backwards to round it. Repeat 10 times.
- Standing back extensions: Stand up, place your hands on your lower back and gently lean backwards. Repeat 5 to 10 times. This is especially useful after long periods of sitting.
- Knee hugs: Lie on your back and draw one or both knees towards your chest. Hold for 20 to 30 seconds.
- Hip flexor stretch: Kneel on one knee with the other foot in front, then shift your weight forwards until you feel a stretch at the front of the hip. Hold for 30 seconds each side.
- Glute bridges: Lie on your back with knees bent and lift your hips off the floor, squeezing your buttocks. Repeat 10 times.
- Walking: A daily 20 to 30 minute walk is one of the best things you can do for a sore back.
Use heat or cold
A warm pack or hot water bottle on the lower back can relax tight muscles. Some people prefer a cold pack in the first few days after a flare-up. Use whichever feels better and always wrap it in a towel.
Stay active and avoid bed rest
Current NHS guidance is to keep moving and carry on with normal activities as much as you can. Long periods of rest tend to slow recovery. Over-the-counter pain relief may help in the short term, but speak to a pharmacist or GP if you are unsure what is suitable for you.
Still struggling despite these changes?
Still struggling despite these changes? Our NHS-experienced physiotherapists can assess your back and give you a plan tailored to your work and lifestyle.
Book your appointment today, with weekend slots available.
Physiotherapy for Lower Back Pain: How a Physio Can Help
Home changes work well for many people, but they do not tell you why your back hurts. That is where physiotherapy for lower back pain comes in. A physio identifies the structures and habits driving your pain and treats the cause, not just the symptoms.
At Priory Physio, lower back pain treatment usually includes:
- A full assessment. We ask about your work, sitting habits, sleep and activity, then examine your movement, posture, strength, joints and nerves. This helps us work out whether your pain is coming from muscles, discs, joints or nerves.
- A clear explanation. You leave knowing what is going on and what to expect, without confusing jargon.
- Hands-on treatment. Manual therapy may be used for some people alongside exercise and active rehabilitation where clinically appropriate.
- A personalised exercise programme. Targeted exercises build core, glute and back strength and improve hip mobility. These are the changes that stop pain coming back.
- Workstation and driving advice. Practical tweaks to your desk, chair and daily routine, based on how you actually spend your day.
- Long-term pain support. If your back pain has lasted for months, our persistent pain management approach helps you build confidence and get back to normal activity.
Every plan is built around you and your goals, whether that is getting through a working day comfortably, driving to see family or getting back to the gym. You can learn more about our team and approach.
No GP referral needed.
You can book directly with our HCPC-registered physiotherapists in Hastings.
Book a lower back pain assessment or call us 07494 247265.
When to See a Physio for Back Pain
Many people wait months before seeking help, by which point pain has often become harder to shift. As a general rule, it is worth booking a physiotherapy assessment if:
- Your lower back pain when sitting has not improved after two to three weeks of self-care
- Pain keeps returning every time you sit for long periods
- Pain, tingling or numbness spreads into your buttock or leg
- Pain is affecting your sleep, work, driving or daily activities
- You are unsure which exercises are safe or helpful for you
- You have had several flare-ups and want to stop them happening again
An earlier assessment can help you understand your symptoms, identify appropriate activity modifications and start a suitable rehabilitation plan.
Red flags: when to get urgent medical help
Rarely, back pain can be a sign of something more serious. Call 999 or go to A&E straight away if you have back pain with:
- Numbness or tingling around your genitals, bottom or inner thighs
- New difficulty passing urine, or loss of bladder or bowel control
- Weakness or numbness in both legs, or unsteadiness on your feet
These can be signs of cauda equina syndrome, which needs emergency treatment.
See your GP urgently, or call NHS 111, if your back pain comes with a high temperature, unexplained weight loss, a history of cancer, severe night pain that does not ease with rest, or follows a significant fall or accident.
Frequently Asked Questions
Why does my lower back hurt when sitting but not when standing?
Sitting flattens the natural curve of your lower spine and increases pressure on the discs and ligaments. Standing and walking spread the load more evenly, which is why many people feel relief as soon as they get up.
Is lower back pain after sitting serious?
In most cases, no. It is usually mechanical and improves with movement, better posture habits and exercise. Seek urgent help if you notice any of the red flags listed above.
What is the best sitting position for lower back pain?
Sit with your back supported, feet flat and knees level with or slightly below your hips. Above all, change position often, because no single posture is comfortable for hours.
How long does lower back pain from sitting take to go away?
Most episodes ease within a few weeks with the right changes. If pain lasts longer than that or keeps coming back, a physio can help you find and fix the cause.
Do I need a GP referral to see a physio?
No. You can book directly with Priory Physio without a referral. If we think you need to see a GP or specialist, we will tell you.
How many sessions will I need?
It depends entirely on your condition and how it responds to treatment. We will give you an honest estimate after your first assessment rather than lock you into a fixed package.
Is physiotherapy suitable for long-term conditions like arthritis, or only for injuries?
Physiotherapy is not just for injuries. It is also can play an important role to manage long-term conditions like arthritis, helping to reduce pain, maintain mobility and keep you independent for longer.
Get Expert Help for Lower Back Pain in Hastings
You do not have to keep working around the pain. Whether your back aches at your desk, in the car or on the sofa, our NHS-experienced, HCPC-registered physiotherapists will find the cause and give you a clear, personalised plan to get you moving comfortably again.
We also treat neck pain, sciatica, muscle spasm and a wide range of other conditions. View all our physiotherapy treatments.
Book your appointment today with weekend appointments available, or call the clinic on 07494 247265.