Anatomy Of An Office Chair Part 2: The All Important Seat

This week we move on to the heart of any office chair, the seat. It's easy to think that the seat doesn't matter too much as long as it's comfortable. Nonetheless there is a lot more to office chair seats than it may seem. The chair may have loads of levers attached to it, however if those controls don't pull the right strings they won't be of much use.

It's not the levers that matter it's what they control and the way the seat operates that is important.

Seat functions
At first glance the seat of an office chair appears to be the place to park your butt while you work. While this is true there is a lot more to it than this. There are 2 functions that are critical if you are going to stay comfortable for any length of time.

Let's dive into them now.

Seat depth adjustment
When you sit for prolonged periods you may well find you suffer discomfort in your legs. One of the main reasons this happens is because the depth of the seat is wrong for the length of you legs.

seat slide

Seat Depth Adjuster on HAG 4400 Chair

So what results is your legs aren't properly supported and muscles get overloaded leading to pain.

A good seat will include a means of adjusting the depth to suit your legs.

This is usually done with a lever allowing the seat to slide forwards or backwards to set it to the correct depth for your comfort.

On some chairs the back moves in and out, overall it achieves the same result.

That's one problem solved, here's the next one to fix.

Seat tension adjustment
We all need to relax and recline in our task chair from time to time. Imagine if you just sat hunched over your work all day and couldn't recline, it would be a nightmare wouldn't it?

tension knob

Tension Controller On HAG H09 Chair

Nearly all office chairs recline, however it's only useful if it's easy to use.

Humans vary a lot in size and weight. Consequently when you recline in your chair it needs to be tuned to your weight so you can do so smoothly.

This is achieved by an under seat adjuster, usually a knob set centrally at the front. Turning it one way increases the amount of pressure required to recline easily. And the opposite way to decrease the pressure needed.

There is nothing worse than constantly fighting with your chair when you want to lean back. With a tension adjuster your problem is over and it's a one off thing too. Set it and forget it.

And some manufacturers have even automated these problems.

Self adjusting seats
Quite a few chairs now are designed to automate these settings.

Quite simply as you sit in the chair it senses your size and weight and automatically compensates without the need for any manual adjustment.

As technology improves more and more seats will come with useful like this.

So that's taken care of the critical functions you need, lets turn to the finishes office seats come in.

Seat upholstery
More often than not the seat will be finished in either fabric, leather, vinyl or mesh. In the case of the first 3 they can all be applied to the same basic make up which usually comprises a foam core supported on either a wood or plastic under frame. In the case of mesh it doesn't have these components and is usually self supporting being stretched over an outer plastic frame.

Let's consider each finish in a little more detail.

Fabric upholstery
This is the commonest finish and comes in a huge range of colors and qualities. It's always a good idea to check how hard wearing a material is and this is usually expressed as the rub count. The higher the number the better.

Leather upholstery
Leather varies hugely in quality. So when you see a leather chair for $50 be assured the leather will be of very low quality. If you want a good leather you should look for a hide finish. This is premium leather and doesn't come cheap, expect a 3 figure on cost for the best ones.

Vinyl upholstery
This is useful for where you have a finish that may get dirty quickly and can be easily wiped clean. It's also used as faux leather on many cheap chairs.

Mesh upholstery
The great thing with mesh is it's breathable and allows good air circulation. This is great for those hot sweaty summer days. There is also a wide ranging difference in the quality and comfort of mesh upholstery. Poor quality ones should be avoided as they don't support you properly and just sag as you sit on them.

Top quality mesh is often built up in multiple layers in a 3d structure to ensure your body is properly supported.

Selecting the right upholstery for your needs will come down to personal preference and available budget.

Here's a quick summary of what we've covered.


  • The functions on an office chair seat are critical for good comfort
  • Seat depth needs to be adjustable to fit your legs
  • Seat tension needs to be easily changed to match your weight
  • Some chairs adjust automatically
  • Upholstery may come in fabric, leather, vinyl or mesh

In the next post we move on to chair arms and what you need to look for and avoid.


Why Is Selecting The Right Office Chair Mechanism So Important? The Function Factor

So what’s the big deal with an office chair mechanism?

Imagine you had a large lawn that needed to be mowed every week in summer, it’s unlikely you would use a push mower. Its lack of flexibility would make your task unbearable as you huffed and puffed cutting it.

Well the wrong mechanism can easily land you in a similar situation and make your working day intolerable.

In this article we’re going to take a look at what controls every office chair – the chair mechanism.

Here are the 3 areas we're focusing on:

  • What exactly is an office chair mechanism?
  • What functions on an office chair mechanism are vital?
  • What types of office chair mechanisms should you avoid?

Let's begin with the mechanism itself, the chair's gearbox.

What exactly is an office chair mechanism?

office chair mechanism

Office Chair Mechanism On Underside Of HÅG Chair

The mechanism is the heart of any office chair, quite simply it is the means by which the core functions of your chair are controlled.

It’s mounted underneath the chair seat and because it’s hidden from view most people never give it a second thought.

Which is just as well because they can look pretty strange.

Seating manufacturers generally do a pretty poor job in explaining what the different functions of a mechanism are for. They assume that because they know what the various types do that there is no need to explain things to the end user. So let’s cut through the different types of mechanism and look at what matters.

What chair mechanism functions must you insist on?
Mechanisms come with all sorts of features, some are essential and some are useless. Very often the things you need for flexible working are the functions most often missing.

Which ones do you really need? It’s safe to say all mechanisms will let you adjust the height of your chair, that’s a given. Aside of this there are 3 essential functions you need to insist on.

First, you need to make sure that the chair reclines properly meaning that when you lean back in it the back reclines too. Often chairs have a lever that locks the back in different preset positions. If you are using your chair for working actively at your computer this is not a good idea because you will soon feel seized up and stuck in a fixed position.

Next, and hugely important the chair needs to include a tilt tension control so it can adapt properly to your posture as you move. What this does is to allow you to set the pressure applied when you lean back and forwards in your chair. Quite simply it lets you set up the chair for your own weight so that reclining is natural and not forced.

Lastly, and most important of all the chair’s controller needs to include a seat slide mechanism to take account of your leg length. Without it short built users can find themselves perched on the edge of the seat unable to rest their back on the seat’s back.

Taller people have the opposite problem. Their legs overhang the seat edge by miles even though their back is hard up against the chair’s back. And even when you are average built things like upper and lower leg length variation still mean you shouldn’t skip this key adjustment.

What types of office chair mechanisms should you avoid?
Steer clear of any mechanism which only has a single lever control. It’s lack of flexibility will quickly drive you nuts, because all you will be able to do is raise and lower your seat and if you're lucky lean back to a limited degree.

And don't fall for chairs that come with more levers and knobs than you might find on an airliner. Lots of controls don't automatically lead to flexibility and comfort, the right controls are what matter.

So, make sure it does what you need. Don't assume because it has loads of paddles and buttons it must be OK, always check.

Here are the key points we’ve covering in this article:

  • What exactly is an office chair mechanism?
  • Why certain functions on an office chair mechanism are key
  • Why some types of office chair mechanisms are a mistake and should be avoided

Here’s where you can find a quick summary of great office chairs that include the vital functions you need so you don’t end up with a push mower model.


How To Avoid Buying A Halloween Horror Office Chair: 3 Ghoul Rules You Need To Heed

Avoid Halloween Horror Chairs

Just a few days from now it will be Halloween and families will be having parties with kids enjoying their tricks and treats. Fortunately it’s all just harmless fun and folks have a great time as the nightmares are only make believe.

If you are looking to replace your office chair you need to avoid making for real Halloween mistakes. Because if you get it wrong the ghouls will be with you every minute you sit in your new chair.

It’s actually very easy to be sucked in by what seems like a great office chair. When you are shopping in your local office supplies store chances are you may be tempted by the glitzy display of office seating. And when you sit in the sample chair it feels comfortable too. That's not surprising, when you've been wandering around for a while it’s nice to take the weight off your feet, so it likely will feel welcoming.

It’s only when you've used a chair for an hour or two that its limitations become all too clear.

In this article we’re going to take a look at 3 key ways of avoiding buying the wrong office chair

  • Buying a chair with no tension adjustment
  • Buying a chair with fixed arms
  • Buying a chair solely on price

So let’s look at the first problem.

Don’t buy a chair which lacks tension adjustment
When you spend all day working in a desk chair it’s only natural that you want to relax and recline every now and then. Many cheap chairs have no way of altering the pressure required as you lean back in them.

What you get is a preset tension based on the manufacturer’s best guess on what’s right. You might get lucky, however for many it soon becomes a nightmare.

Light framed people find themselves gripping the chair arms and straining to get the thing to go back. And as soon as you relax the damn thing flips you forward again.

Heavy built people have the opposite problem. The chair just lurches backward without warning threatening to pitch you on the floor.

So, make sure any chair you're thinking of buying let’s you adjust the tilt tension. Some automatically adjust to suit your weight but you won’t find this feature on budget chairs.

Onto the next rule.

Don’t buy a chair with fixed arms
The right arms on an office chair are important. Humans all come in different sizes and it simply isn’t possible to cater for individual preferences with a fixed arm.

You need to make sure the arms on your chair are height adjustable. That way you can set them so your lower arms are comfortably supported with you shoulders resting naturally.

Some arms have additional features like being able to move them forwards, backwards or in and out. These arms are often called highly adjustable and the added features can be useful.

And the last rule.

Never buy an office chair just because it’s cheap
More often than not cheap office chairs turn out to be a very poor bargain in the long run. Occasionally there is an opportunity to get a genuine reduction on a quality chair, maybe a discontinued range or ex showroom item. And that’s fine.

However, what you must avoid is chairs priced around $100 or less. The reason is simple. Chairs like this are made to meet a price point. The only thing on the maker’s mind is how it can cut costs to meet the price. There are a lot of things in a task chair you can’t see and this is where corners get cut.

Low quality seat foam that goes flatter than a squashed ant after a couple months use.
Poor quality steel components that quickly wear and become sloppy or break altogether.
Cheap upholstery that just doesn't last.

Buying on price alone truly is a false economy tempting as it may seem.

So to save yourself from horror chairs:

  • Make sure the chair has tension adjustment to let you relax easily when you need to
  • Fixed arms rarely give good support; make sure you can adjust the height of the arms
  • Don’t buy solely on price; it’s a false economy which you will quickly regret.

Make these part of your selection criteria and your chair won't haunt you the rest of the year.

Here's a useful video and article on the key features that make up a proper ergonomic office chair to help point you in the right direction.


Are The Missing Functions On Your Office Chair Ruining Your Health?

Most biking nuts will have ridden on a fixed wheel at some stage and a moment’s loss of concentration can rapidly inflict pain on the rider. Let me explain. A fixed wheel only has a single cog on the rear wheel meaning the rider’s pedalling pressure is always the same uphill, downhill or on the flat. So there are no gears to take the strain.

And if that wasn't bad enough there is no freewheel function you have to keep pedalling and you actually brake or stop the bike by gradually slowing your pedalling and then back pedalling when the bike has slowed sufficiently to bring it to a halt.

So, there you are biking along and you forget you’re using a fixed wheel so you relax and stop pedalling and wham! Before you know it the pedals are making mincemeat of your feet and ankles because they keep rotating and clattering them as they do so.

Chairs with missing functions are a lot like fixed wheel biking, you can never relax in them. They always seem to be controlling how you move in them and inflicting pain with their lack of flexibility.

What functions do all office chairs have?
It’s fair to say that all office chairs will have at least 2 functions, because without them they couldn't perform at all.

First, they all have height adjustability and this is pretty important because the ability to be able to set the correct seat height relative to the user’s leg length is essential.

Second, they all have a 5 star swivel base, which is critical for being able to move quickly and easily when addressing work at your desk. If you’ve ever used a 4 legged chair working at a computer you'll know how limiting it can be the first time you want to move to reach something.

Many believe that these 2 functions are all you need, let’s look at why they will never be sufficient on there own.

Why aren't they enough?
OK, so you might think that being able to move freely around your desk area and setting the height of your chair’s seat to suit your body is enough. Sure it’s a good start and to be honest if you only work at a desk for an hour a day you may get away with it. For those working long hours at a workstation the lack of other functions will quickly become apparent.

The inability to alter the chair’s back position will pretty soon start causing you back pain and probably neck and shoulder discomfort too. Unless you are extraordinarily lucky the back won’t be correctly placed for good support.

Incorrectly positioned legs is a prime cause of leg pain, not surprising when you think about it because when you place any part of your body in an unnatural position it won’t be long before it starts resonating pain signals.

There are other potential problems when you don’t make sure you get the right features.

What other features should you insist on?
You need to be able to move the chair’s back up and down to get it placed in the optimum position for the shape of your back. Having said that some chairs come with fixed full height backs which include an integrated adjustable lumbar support and this achieves the same thing. So, always make sure your chair will allow you to set the back adjustment to fit you.

No two people’s legs are the same length and so you must make sure your seat’s depth can be set to match with your leg length. This is usually achieved with a seat slider or occasionally the back depth can be moved in and out. Either way, you need this functionality and unfortunately far too many chairs don't allow this, which is frankly ridiculous.

Arms should always be adjustable to let you position them in such a way that they support your lower arms and shoulders naturally. Fixed arms are little more than a lottery and too many are based around some funky cool shape without any thought as to whether they will be comfortable.

Being able to set the spring tension of your chair’s recline is another key function to insist on. Without it, light framed people will always feel they are fighting with their chair back when they recline. And heavy built people may well find the opposite effect, as the chair just seems to fall away on reclining. So, insist on tilt tension and leave yourself in control when relaxing.

Let’s quickly recap on the points I've outlined in this article

  • Seat height adjustment and a wheel base isn't enough for proper comfort
  • Proper comfort can only be achieved with proper functions
  • Make sure your chair’s back adjusts
  • Make sure you can alter seat depth to suit your leg length
  • Adjustable arms are necessary for proper arm and shoulder support
  • Tilt tension put you in control when you recline, not the chair

When you insist on these important functions you greatly increase your chance of good sitting comfort. Don’t get stuck with the seating equivalent of fixed wheel biking, always ensure your chair has the necessary gears.

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