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What Does The Knob Under My Office Chair Do? 5 Common Knobs

What Does The Knob Under My Office Chair Do? 5 Common Knobs

If you’ve invested in your first office chair, it can be an exciting time. Finally, you can sit at your desk for hours with the utmost comfort.

The best part is your comfort is not only limited to the soft cushion, the arm, back, and headrest, and the easy movement. The knobs under your office chair are also there to make you very relaxed while at your desk.

If you’re new to the office chair mechanics, you might be wondering what all these knobs are for. Or, if you’re still looking for a good office chair to buy, it’s a good idea to know first what the knobs can offer.

Here, we’re going to talk about the 5 most common knobs under an office chair. We’ll explain what it’s for, how to use it, and where to locate it.

So let’s get started!

5 Common Knobs Under An Office Chair

Before we begin, it’s important to note that the knobs we mention here might not be in your office chair. This is because office chairs have different designs and come with different mechanics.

But since we’re mentioning the most common ones, your office chair will probably have one or two, or all, of these knobs.

One last thing. Your office chair might have the same mechanics but are located in a different area. Or, it might come in a different shape.

1. Chair Tilt Tension

Chair Tilt Tension | NBF 30 Second Office Tip

Do you ever feel the urge to recline in your chair for a short computer break?

Well, with the office chair’s tilt tension, you now can!

This knob allows you to increase or decrease the tension of the chair. If you decrease the knob, the tension also decreases, making the office chair rock. If you want it to lock at a certain position, say, a little bit reclined, turn the knob the other way to increase the tension.

You’ll know which way to increase or decrease it because the knob has a + and – marking.

If ever the knob is hard to turn, use a wrench or a Channellock to adjust it.

The most common location of the chair tilt tension is underneath the seat toward the front. You can easily spot it as it’s the biggest round knob. However, some office chairs have the tilt tension located at the side of the chair as small knobs or even cranks.

So this is a great office chair mechanic to have because you get to decide the tilt that’s most comfortable for you.

2. Height Adjustment

Ergonomic Office Chair - Seat Height Adjustment

It’s very disappointing if the office chair you bought is too tall or too short for you. Your legs and feet will feel a lot of pressure after several hours of sitting on it. This actually happens more often than not.

This is why the height adjustment knob is another of the most common office chair mechanics. With this knob, you get to decide the height that’s perfect for you.

The height adjustment knob sticks out of the seat’s side for better access. If many knobs are sticking out, it’s usually the one in the middle.

If you want to lower the height, pull on the knob while adding weight so the seat will sink. To heighten it, pull on the same knob, but this time, don’t add your weight. It’s as easy as that.

The way it works is that the knob connects to a hydraulic or pneumatic metal shaft below the seat. It is this metal shaft that gives the seat the upward and downward movement.

Something that always seems to happen over time is that the metal shaft and knob no longer work. The office chair always sinks down when sat upon. If this happens to your office chair, click here to learn how to fix the problem.

So with this knob, you don’t have to worry about whether your office chair is too tall or too short for you.

3. Back Height Adjustment

How to set your office chair back height

What if the height of your office chair is fine but the back support is too high or low for you? Or, what if your office chair’s backrest has a bulge for your lower back to contour into but is positioned too high or low?

There’s a knob for that, too!

You’ll find this knob right under the backrest. Turn it to release tension, then raise or lower the backrest to the most comfortable height for you. Once you find that position, tighten the knob again.

If you get one of the newer office chairs, the back height adjustment might be a ratchet instead of a knob.

If this is the case, you can adjust it by placing your hands on the base of the backrest and pull upward. With each pull, you’ll hear a click as the height pawl locks onto the ratchet.

To lower, pull the backrest all the way up until there are no more clicks and slide it down.

One problem with the ratchet technique is that it has fixed heights. With the knob, you get to position it at a very specific height.

The ratchet technique is easier to adjust, though.

4. Seat Angle Adjustment

Ergonomic Office Chair - Seat Angle Adjustment

If you’re going to be sitting for hours on your office chair, it’s best to have a good posture, upright with an arched spine. Even if your office chair’s backrest has a bulge, the seat angle still plays a huge role in an upright posture.

The knob that controls the seat angle adjustment is the first knob sticking out from the front. If you twist this knob clockwise, the front of the seat will drop down. Likewise, if you twist it counterclockwise, the back of the seat will be the one to drop down.

Most office chairs allow you to tilt the seat 6° forward and 3° rearward.

5. Seat Depth Adjustment

How to Adjust Your Office Chair Seat Depth Correctly

The seat depth adjustment also helps with good posture and lumbar support. Not only that, but it also makes sure circulation in your legs isn’t cut off.

If the back of your knee touches the seat, there might be a pressure that cuts off blood circulation. You also don’t want to keep the back of your knees too far from the seat as that could cause backaches.

Good advice is to leave at least a 2 finger distance from the back of your knee to the front of your seat.

If your office chair comes with a seat depth adjustment, you’ll be able to get the right seat depth for you.

You won’t have trouble finding this knob since it’s the only one on the left side. The moment you lift the knob up, you can move the seat inward and outward.


So these were the 5 most common knobs under an office chair. All these knobs are there to make your office chair perfect for you.

Check out your office chair to see what knobs you’ve got. Or, if buying a new office chair, look for the knobs that’ll give you the most comfort and best posture.