You have owned the chair for two years and never touched the knob underneath it. Then a colleague sits down, twists one thing, and the seat feels completely different. Nothing was broken — they simply matched the chair to their body, which is what every lever, paddle and dial is there for.
Most office chairs hide four or five adjustments, and each one corrects a specific mismatch: your height, your thigh length, the curve of your lower back, how much you like to lean. Set them in the wrong order and you will keep chasing the problem. A modest chair set up properly beats an expensive one nobody has touched.
The Tension Knob: How Hard the Chair Pushes Back
This is usually a knurled knob under the front of the seat, or a dial on the side of the mechanism. It controls the spring that resists your recline. It does not decide how far back you go — the tilt lock does that. It decides how much effort leaning back takes.
Turn it clockwise to firm it up, anticlockwise to lighten it. Most people leave it at the factory setting, which suits almost nobody.
The test is simple. Sit back with your feet flat on the floor and let your weight go into the backrest. If you have to grip the desk or push hard with your legs to return upright, the tension is too high. If you flop backwards the moment you relax, it is too low. Aim for the point where a light push takes you back and your body comes forward again on its own.
If you need your arms to sit up again, the tension is set too high.
Heavier sitters usually want more tension, lighter sitters less — but how far you like to lean back matters more. If you barely recline, a stiff spring is fine. If you like to lounge, loosen it.
The Tilt Lock: Stop the Rock When You Need To
The tilt lock is the lever or paddle, normally on the left beneath the seat. It locks the backrest at a fixed angle. Many chairs offer several locking positions; some lock only fully upright or fully back, with a free-floating recline in between.
Free-float is the setting most office chairs are designed around. Sitting bolt upright for hours tires your back. A slight recline lets the chair move gently as you shift, so pressure travels around rather than landing on one spot all day.
Leave it unlocked for general work, and lock it when you want a fixed position — reading a long document, taking notes, or when the rocking distracts you. If the lever feels stiff, lift your weight off the backrest before trying again rather than forcing it.
The Seat Slider: Depth, Not Length
Pull the paddle under the front of the seat and the pan slides forward or back, usually by a few centimetres. The adjustment exists because thigh length varies enormously between people of the same height.
Aim for a gap of roughly two or three fingers between the back of your knee and the front edge of the seat. Sit with your back against the backrest, then slide.
- Too far forward: the front edge digs into the back of your thighs and can restrict circulation.
- Too far back: you perch on the front of the seat and lose the back support you paid for.
- No slider? A lumbar cushion or a folded towel behind your back does a similar job.
Set seat height first. If your feet dangle afterwards, a footrest will help far more than fiddling with the slider.
Lumbar Support: Position Beats Pressure
Lumbar controls are the ones people get wrong most often. The pad should sit in the small of your back — around belt height or slightly above — filling the inward curve. It should not press into the base of your spine, and it should not sit so high that it pushes your shoulders forward.
Many chairs allow two adjustments. Height: slide the pad up or down until it lands in the hollow of your back. Depth: a knob or dial moves the pad in and out. Start with a light touch. You should feel supported, not prodded. If it feels like a fist in your back, wind it back.
Fixed lumbar support that lands in the wrong place is common on cheaper chairs. A small cushion, or a rolled towel held on with an elastic strap, will get you closer than fighting the built-in pad.
Armrests, Headrests and the Rest
Armrests should be high enough that your shoulders drop and your elbows sit at roughly a right angle, and low enough that they slide under the desk. If fixed armrests stop you getting close to your keyboard, removing them — usually a bolt or two — is a genuine improvement.
A headrest is for reclining, not for typing. When you sit upright it should sit behind your head, not push it forward. And if your chair has a dial for seat tilt, the pan tipping forward slightly, leave it flat unless a gentle forward slope genuinely suits the detailed work you do.
The Order That Works
Adjust in this sequence, because each setting changes the ones after it:
- Seat height — feet flat on the floor, thighs roughly level or sloping slightly down.
- Seat depth — two or three fingers between knee and seat edge.
- Lumbar pad — height first, then depth, kept light.
- Tilt tension — loose enough to lean back easily, firm enough to come up without your arms.
- Tilt lock — unlocked for general work, locked when you want stability.
- Armrests — shoulders relaxed, elbows close to a right angle.
Give it a couple of days, then tweak. If you share the chair, mark your settings with a strip of tape on the tension dial or a pencil line on the slider; it takes seconds to find your position again. And if back or neck pain persists once the chair is set up properly, speak to a physiotherapist or your GP rather than assuming the furniture is the whole story.
Photo: aboodi vesakaran / Pexels
