Backrests on office chairs adjust through height slides, recline-lock levers, or tilt-tension controls, and the exact mechanism varies by model.
Most people start pulling at the backrest without realizing their chair may offer several separate adjustments: height, angle, and tension all do different jobs. Knowing which control does what instantly turns a confusing tangle of levers into a comfortable setup. Before anything else, sit in the chair — body weight helps engage most mechanisms and gives immediate feedback on whether the support actually fits your spine.
Types of Backrest Adjustments And How Each Works
Office chairs typically include one or more of these systems, usually controlled from the side of the seat or just below where the backrest meets the seat pan. The three core adjustments serve separate purposes.
Backrest height moves the entire back panel up or down to align with your torso length. On many models this involves a lever that unlocks a slide, allowing the back to glide to a new position before locking into discrete holes. Some chairs only allow lowering after first raising the backrest fully to the top, so check that before assuming the mechanism is stuck.
Backrest angle and recline lock controls how far backward the backrest tilts. A lever-based system typically unlocks the angle while you push back, then locks it when you release. Note that recline tension and recline lock are separate: a tension knob or wheel controls resistance, while a lever locks the angle itself into place.
Tilt tension, often a rotating wheel or knob under the seat, changes how much force is required to lean back, without fixing a specific angle.
Finding The Right Control For Your Chair Model
The control locations and motions differ enough between brands that one universal set of steps would mislead you. Match your chair to the listed mechanisms below or use the general sequence that follows.
| Chair Model | Backrest Adjustment Type | How To Adjust |
|---|---|---|
| Herman Miller Embody | Spine curvature (BackFit knob) | |
| Herman Miller Aeron | Lumbar height and depth | Apply equal pressure to both ends of the lumbar pad to slide it vertically along its track; remove, flip, and reinsert it to swap thickness sides. |
| Ergohuman models | Tilt angle, tension, and height | |
| IKEA MILLBERGET | Backrest angle lock | Sit down, pull the lever up to unlock, lean the backrest forward or back, then release the lever to lock. |
| IKEA JÄRVFJÄLLET | Backrest recline lock | Lean back, then push the lever forward to lock the angle; pull it back to release. |
The Step Order That Works On Most Chairs
If your chair does not appear in the comparison above, or you want a dependable starting sequence, this general flow works for most adjustable models. Sit first, then follow each stage one at a time.
- Sit in the chair with your feet flat on the floor — your weight is needed to operate most levers and properly test the fit.
- Locate the backrest control, typically a lever, knob, or wheel on the side of the seat or at the junction where the backrest meets the seat pan.
- Unlock the mechanism by pulling the lever, pushing it forward, or turning the knob, depending on your model.
- Move the backrest to the angle or height that supports your spine’s natural curve — keeping feet flat and avoiding a hunched or over-reclined position.
- Lock it back by releasing the lever or pushing it into the locked position, then test the recline to confirm the setting holds your weight.
One honest distinction matters here: backrest height and lumbar height are not the same adjustment on chairs that have both. Raising the whole back panel does not necessarily reposition the lumbar support curve. If your chair has a separate lumbar control, adjust that independently so the support targets the small of your back rather than your mid-back. A properly positioned backrest also eases pressure on your neck during computer use by helping you stay upright.
Before you buy rather than adjust, our hands-on tested roundup of the best chair backrest supports on the market can point you toward models that get this right out of the box.
FAQs
Why won’t my chair backrest stay in position?
A backrest that slowly sinks or fails to lock usually means the lever was released before the backrest fully settled into place, or the locking teeth are worn. Re-sit, re-engage the lever, and push the backrest firmly into the desired angle before locking again. If the mechanism still slips, the lock mechanism itself may need repair.
How do I reduce the pressure when I lean back in my chair?
Turning the tilt-tension knob or wheel counterclockwise reduces the force required to recline. This is a different adjustment from the recline lock lever that fixes the angle. Test only the resistance knob first, and avoid turning it so loose that the backrest flops backward unexpectedly.
Is a chair backrest supposed to lean back easily?
Only if you have loosened the tension. A healthy ergonomic chair supports a neutral working posture while allowing you to recline under deliberate pressure, then returns you upright without fighting your movements. If the chair pushes you forward too aggressively, loosen the tension slightly or reduce the recline angle with the lock lever.
Getting the Fit Right for Your Posture
Adjust for the goal of the whole body, not just the lever itself. The final position should keep your feet flat on the floor, your knees near a 90-degree angle, and the backrest support pressed gently into your lower back’s natural curve.
References & Sources
- Herman Miller. “Chair Adjustments.” Official support hub linking to model-specific Embody and Aeron adjustment documentation.
- Herman Miller. “Embody Chair Adjustment Guide” (PDF). Details the BackFit knob control and spine-fit instructions.
- Herman Miller. “Sayl Chair Adjustment Guide” (PDF). Reference for lumbar pad removal, flipping, and reinsertion steps on related models.
