Last Updated: May 2026 | Some links on this page are affiliate links. This costs you nothing and helps fund our independent research.
Most desk workers sit incorrectly — not through carelessness, but because their workspace is not configured to make correct posture the natural default. When the chair lacks lumbar support, the monitor is too low, or the desk is at the wrong height, the body adapts by finding compensatory positions that reduce immediate discomfort but create cumulative strain over hours and months.
The goal of correct sitting posture is not to hold yourself rigidly in an ideal position through effort. That approach fails within minutes when concentration returns to work. The goal is to configure your chair and workspace so that the correct position is also the most comfortable and effortless one — so good posture is maintained automatically, without conscious effort.
This guide covers exactly how to achieve that.
Why Posture Matters More Than You Think
The lumbar spine has a natural inward curve — the lordotic curve. When this curve is supported, the muscles surrounding the lower back can rest. When it is not supported — when the spine flattens or rounds — those muscles must contract continuously to maintain an upright position. Over a six-hour working day, this sustained muscle activation produces fatigue, tension, and eventually the chronic pain that most desk workers experience.
The cervical spine — the neck — has a similar natural curve that is disrupted by forward head posture. A screen that is too low, a slouched sitting position, or hunching forward to type all push the head in front of the shoulders, increasing the load on the cervical spine with every inch of forward displacement.
Correct sitting posture supports both curves passively — the chair and workspace configuration doing the work, not the user’s muscular effort.
The Correct Sitting Position: Step by Step
Step 1 — Set Seat Height First
Seat height is the foundation. Everything else is adjusted relative to it.
Adjust the seat height until:
- Your feet rest flat on the floor — not on tiptoes, not dangling
- Your thighs are roughly parallel to the floor — horizontal or very slightly declining
- Your knees are at approximately 90 degrees
If your feet do not reach the floor at the correct seat height for your desk, use a footrest. Do not lower the chair to reach the floor if doing so raises the desk to an uncomfortable height — the footrest is the correct solution.
Signs your seat height is wrong:
- Feet dangling — seat is too high
- Knees higher than hips — seat is too low
- Having to reach up to the desk — seat is too low relative to desk
Step 2 — Set Lumbar Support Height
Sit all the way back in your chair so your back is in full contact with the backrest. Do not perch on the front edge.
Adjust the lumbar support up or down until it presses firmly and comfortably into the inward curve of your lower back. This curve — the lordotic curve — sits between your waistband and the bottom of your ribcage for most people. If you are unsure of its exact position, place your hand behind your lower back and feel for the inward curve, then position the support there.
The lumbar support should feel as though it is gently filling the gap between the chair and your lower back. It should not push the lower back forward uncomfortably, and it should not be so far from the spine that it makes no contact. Firm, consistent contact with the natural curve is the target.
Signs lumbar support is wrong:
- Lower back rounding or flattening against the chair — support is too low or too far
- Lower back pushed forward uncomfortably — support is too high or too close
- No noticeable support — support needs to be raised or chair lacks adequate lumbar system
Step 3 — Set Armrest Height
With your shoulders fully relaxed — not elevated, not deliberately pulled back — adjust the armrests until your forearms rest lightly on them with elbows at approximately 90 degrees.
The key test: your shoulders should be completely relaxed when using the armrests. If they rise toward your ears, the armrests are too high. If you hunch forward or downward to reach them, they are too low.
Correctly positioned armrests remove the sustained shoulder elevation and upper trapezius tension that produces neck pain and upper back discomfort during long sessions. This is one of the most impactful adjustments and one of the most commonly overlooked.
Signs armrests are wrong:
- Shoulders elevated when resting forearms on armrests — too high
- Hunching forward to reach armrests — too low
- Reaching outward to rest forearms — too wide
Step 4 — Check Seat Depth
If your chair has seat depth adjustment, set it so there is a two to three finger gap between the front edge of the seat and the back of your knee when sitting fully back against the lumbar support.
If your chair has a fixed seat depth, sit fully back and assess whether the front edge of the seat presses into the back of your knee. If it does, the seat is too deep for your leg length and you will need to either sit forward — losing lumbar contact — or find a chair with adjustable seat depth, such as the Clouvou Clever Seat.
Step 5 — Set Monitor Height
Sit correctly in your adjusted chair. Look straight ahead. The top of your monitor should be at approximately eye level. The centre of the screen should be at a very slight downward gaze — you should not be looking significantly downward or upward.
If the monitor is too low — which it almost certainly is if it sits flat on the desk — raise it. A monitor riser (£20–£35) is the simplest solution. A monitor arm provides more precise adjustment.
Signs monitor height is wrong:
- Chin dropping to look at the screen — too low
- Looking upward at the screen — too high
- Leaning forward to see clearly — too far, or prescription glasses may need checking
Step 6 — Check Keyboard and Mouse Position
The keyboard should be close enough to your body that your elbows stay at approximately 90 degrees when typing — not reaching forward. Reaching forward to type causes the shoulders to protract and the upper back to round, which compounds lumbar strain.
Your wrists should be in a neutral position when typing — neither bent upward nor downward. If the keyboard angle forces wrist extension, a negative-tilt keyboard tray or a lower desk resolves this.
The mouse should be directly beside the keyboard at the same height. Reaching across the desk to a far-right mouse creates lateral shoulder tension that builds through the working day.
What Correct Posture Looks and Feels Like
When everything is configured correctly, this is what you should experience:
Feet — flat on the floor or footrest, relaxed, weight evenly distributed Legs — thighs parallel to floor, knees at 90 degrees, no pressure behind knees Lower back — in gentle contact with lumbar support, no muscular effort required to maintain position Upper back — relaxed against the backrest, not rounded or arched Shoulders — completely relaxed, not elevated or pulled back Arms — forearms resting lightly on armrests, elbows at 90 degrees Wrists — neutral when typing, supported between typing periods Head — balanced over the shoulders, not pushed forward, gaze at slight downward angle to screen
If any of these feels effortful to maintain, the workspace element causing the effort needs adjustment — not the posture.
The Most Common Sitting Mistakes
Slouching. The lower back rounds, the lumbar curve is lost, and the back muscles must work continuously to prevent complete collapse. This is the posture most directly addressed by adjustable lumbar support.
Leaning forward. Typically caused by a monitor that is too far away or too low. The head moves in front of the shoulders, loading the cervical spine and upper back. Correct monitor distance and height eliminate this.
Crossing legs. Creates pelvic tilt and spinal asymmetry that accumulates into hip and lower back strain over long sessions. Keep both feet flat on the floor or footrest.
Perching on the front of the seat. Loses all lumbar support from the chair. Sit fully back against the backrest with the lumbar support in contact with the lower back.
Sitting too long without moving. Even perfect posture creates cumulative spinal load over extended periods. Stand or walk for a few minutes every 30 to 45 minutes regardless of how comfortable the setup is.
Posture and the Chair: The Critical Link
It is not possible to maintain correct sitting posture consistently in a chair that does not support it. A chair without adjustable lumbar support leaves the lumbar curve unsupported — the user must either maintain it through muscular effort (unsustainable) or allow it to flatten (painful). A chair whose armrests do not adjust to the correct height forces shoulder elevation or hunching. A chair whose seat is too shallow forces the user to sit forward.
Correct posture is a function of both awareness and workspace configuration. The awareness fades when concentration returns to work. The workspace configuration is permanent. Getting the configuration right is what makes correct posture the default rather than the aspiration.
👉 See: Ergonomic Chair Buying Guide UK (2026)
👉 See: Best Ergonomic Chairs Under £500 UK (2026)
Movement: The Element Posture Cannot Replace
Correct sitting posture reduces the rate at which sitting creates physical strain. It does not eliminate it entirely. The body requires movement — regular postural variation that loads different structures and allows others to rest.
The practical target: stand or walk for a few minutes every 30 to 45 minutes. This does not require a standing desk, though a standing desk with memory presets makes consistent alternation significantly easier. A phone reminder at the top of each hour is the most reliable tool for building this habit in the first two weeks.
👉 See: Sitting vs Standing Desk Benefits UK (2026)
👉 See: How to Reduce Back Pain at a Desk UK (2026)
Correct Sitting Posture: Quick Reference Checklist
Print or save this and run through it each time you sit down:
- Feet flat on floor or footrest
- Thighs parallel to floor, knees at 90 degrees
- Back fully in contact with chair backrest
- Lumbar support pressing into lower back curve
- Shoulders relaxed, not elevated
- Forearms resting lightly on armrests at 90 degrees
- Wrists neutral when typing
- Monitor top at eye level
- Screen at arm’s length (50–70 cm)
- Keyboard close to body, not reaching forward
- Mouse directly beside keyboard at same height
Run through this at the start of each working day. It takes thirty seconds and ensures the configuration has not drifted from the correct settings.
Final Verdict
Correct sitting posture at a desk is not a technique to practise — it is a configuration to achieve. When the chair is adjusted correctly, the monitor is at eye level, the desk is at the right height, and the keyboard is close, correct posture is the natural result of simply sitting down and working. When any of these elements is wrong, correct posture requires sustained effort that competes with the work itself — and loses.
Configure the workspace correctly, run through the checklist above, take regular movement breaks, and the back pain that most desk workers accept as inevitable becomes preventable.
👉 Best Office Setup for Back Pain UK
👉 Ergonomic Chair Buying Guide UK
👉 How to Reduce Back Pain at a Desk UK
Frequently Asked Questions
What is the correct sitting posture at a desk? Feet flat on the floor, thighs parallel, knees at 90 degrees, back fully supported by the chair’s lumbar support, shoulders relaxed, forearms at 90 degrees on armrests, wrists neutral when typing, and monitor top at eye level. The correct posture should feel effortless — if maintaining it requires effort, a workspace element needs adjustment.
How do I stop slouching at my desk? Slouching is almost always a function of inadequate lumbar support rather than poor discipline. A chair with adjustable lumbar support positioned correctly against the lower back eliminates the postural collapse that produces slouching. If your chair lacks this feature, a lumbar support cushion is a bridge solution while saving for a better chair.
Is it bad to cross your legs when sitting? For occasional brief periods, no. As a habitual sitting position across a working day, yes — it creates pelvic tilt and spinal asymmetry that accumulates into hip and lower back strain over time. Keep both feet flat on the floor or footrest as the default position.
How often should I change position when sitting? Every 30 to 45 minutes at most. Stand up, walk briefly, and return to a slightly different sitting position. Regular postural variation is the element of back pain prevention that correct sitting posture alone cannot provide.
Does an ergonomic chair automatically fix posture? No — it provides the support that makes correct posture effortless, but it must be adjusted correctly for your body. A new ergonomic chair in the default configuration is not set for your proportions. Adjust seat height, lumbar support height, armrests, and recline tension before assessing whether the chair is working.
