Lower back pain from sitting at a desk: causes and fixes

Lower back pain from sitting at a desk usually comes from a mix of slumping, a chair that doesn't fit you, and above all sitting still for too long. For most people the fixes are simple: sit all the way back with your lower back supported and your feet flat, bring the keyboard and screen close enough that you don't lean forward, and get up and move at least once an hour.

That covers the everyday ache most desk workers know. Below are the common causes in a bit more detail, how to set up the chair, a few gentle stretches you can do beside the desk, and the signs that mean you should see a doctor or physiotherapist instead of fixing it yourself. Please read the last section even if your back only aches a little.

Why does sitting at a desk hurt your lower back?

There is rarely one cause. Usually a few small things add up over a long day.

• Slumping. When you perch on the front of the seat or slide down it, your pelvis rolls back and the gentle inward curve of your lower back flattens out and rounds. Holding that shape for hours keeps the same muscles and joints under steady load.
• A chair at the wrong height. Too low and your knees end up above your hips, which tips the pelvis back in the same way. Too high and your feet dangle, so you slide forward to reach the floor.
• A seat that is too deep. If you can't sit back without the seat edge pressing into the back of your knees, you end up perching, with nothing behind you.
• Leaning toward the work. A laptop flat on the desk, a keyboard pushed far back or text that is too small all pull your upper body forward, and your lower back takes the strain.
• Sitting still. This is probably the biggest one. No position is comfortable for hours. Even a well set chair starts to ache if you don't move from it.

It helps to be honest about the evidence. Research has not found one correct sitting posture that prevents back pain, and plenty of people slouch without any trouble. Stress, poor sleep and how active you are overall seem to matter as well. So the aim is not to sit perfectly. It is to sit in a way your back finds easy, and to stop sitting often.

Set up your chair for your lower back

These steps take a few minutes and need nothing more than a towel and perhaps a box.

1. Sit all the way back. Your bottom should touch the backrest. Most of a chair's support is wasted if you perch on the front half.
2. Support the curve. If the chair has adjustable lumbar support, move it to sit in the small of your back, around belt height. If it has none, roll up a hand towel or use a small cushion in the same place. It should feel like gentle support, not a push.
3. Set the seat height. Your feet should rest flat on the floor with your knees about level with your hips or a little lower. If raising the chair to reach the desk leaves your feet hanging, put a footrest, a sturdy box or a couple of thick books under them.
4. Check the seat depth. Leave a gap of a few fingers between the front of the seat and the back of your knees. If your chair lets you slide the seat, adjust it. If not, a cushion behind your back brings you forward a little.
5. Lean back slightly. A backrest tipped a little past upright lets the chair carry some of your weight. Sitting bolt upright for hours is tiring in its own way.
6. Bring the work to you. Keyboard close, at about elbow height. Screen roughly an arm's length off, its top edge near eye level or just under. With a MacBook, that usually means raising the laptop on a stand or a pile of books and typing on a separate keyboard.

Desk setup for a Mac goes through the whole desk in order, with a checklist.

How often should you get up if your back aches?

For most people, movement does more for a sore lower back than any chair. A common suggestion is to shift position every half hour or so and get out of the chair at least once an hour, even if only for a minute or two. Health services generally advise people with ordinary back pain to stay gently active rather than rest, and the same idea applies across a working day.

Some easy ways to build it in:

• Stand up whenever you finish a task, before you start the next one.
• Take phone calls on your feet, or walking.
• Keep your water glass small, so refilling it is a regular trip.
• If you have a standing desk, swap between sitting and standing through the day. Standing for hours brings its own aches, so the change is what helps.
• Walk for ten minutes after lunch.

How often you should get up from your desk looks at the guidance in more detail.

Gentle lower back stretches at your desk

Move slowly, stay in a range that feels comfortable, and breathe normally. Stop if a stretch makes the pain sharper, sends it down a leg, or causes tingling or numbness. If you have a diagnosed back problem, or you are recovering from an injury, ask a physiotherapist which movements suit you before trying these.

Seated pelvic tilt

Scoot forward until your back is off the backrest, feet flat. Slowly roll your pelvis back so your lower back rounds slightly, then roll it forward so your lower back arches a little. Move between the two, gently, five to ten times. It reminds your back that it can move after a long time in one shape.

Seated knee hug

Sitting tall, lift one knee and hug it gently toward your chest with both hands. Hold for a few breaths, then switch legs.

Hip flexor stretch

Stand beside your desk with one hand on it for balance. Step one foot back, keep your back upright and gently tuck your tailbone under, until the front of the back hip feels a mild pull. Hold for a few breaths and switch. Long sitting keeps these muscles short, and many people find this one helps.

Desk stretches for your lower back has more, including a seated twist, a figure four and a standing back bend, with how long to hold each one.

A cat for the slump, a dog for the chair

The hard part of all this is noticing. You start the morning sitting back and end the afternoon perched on the edge of the seat, and the slide happens while your mind is on the work. Notchpals hands the noticing to two characters who take turns at your Mac's notch.

The Posture one checks in a few times a day. If that is Sir Pounce, a posh cat who has yet to be impressed by anyone's posture, the check arrives with the air of a cat inspecting the staff:

Sir PounceBack against the chair, if you please. It's a throne, not a hammock.

A Movement character covers the other half. Its Stand up visit arrives once you have been sitting at the Mac for close to an hour without a break. Nick, a fluffy white spitz, makes the case with a dog's sense of fair play:

NickThat chair has had you for an hour. My turn. Stand up.

Press Done once you are sitting back or on your feet. Notchpals can't tell whether you actually moved; it believes your Done. Press Later and it tries once more a little later, then leaves it.

When to see a doctor or physiotherapist

Ordinary desk backache that eases when you move, and gets better over days or weeks as you change your setup, is very common. See a doctor or a physiotherapist if:

• the pain hasn't eased after a few weeks, or keeps returning despite the changes above,
• it spreads into your buttock or down a leg, especially below the knee,
• you have numbness, tingling or weakness in a leg or foot,
• it stops you sleeping or doing your work.

Get urgent medical help if back pain comes with numbness around your genitals, bottom or inner thighs, new trouble controlling your bladder or bowels, or weakness in both legs. Also get help promptly if the pain follows a fall or accident, comes with a fever or feeling unwell, comes with weight loss you can't explain, or is severe and constant, including at night.

A physiotherapist can watch how you sit and move, work out what is driving your pain, and give you exercises chosen for your back rather than a general list. That is worth more than any stretch in a blog post.