Crafting a Life – Episode 9

The obvious Segway from the last episode is to talk about the ergonomics as well as the “comfort” of chairs.
I should start by saying that the science of ergonomics is very young; it basically started as a result of mechanisation during the Second World War. Aircraft, tanks, artillery, transport vehicles; all needed to conform to the averages of the human body for the particular populations. The cockpit of a Japanese Zero was tiny in comparison to that of an American Corsair, for the obvious reason that the average Japanese at the time was considerably smaller than the average American. Just as importantly, the range of sizes within the Japanese population was narrower than the range of sizes within the American population; American equipment thus needed more scope for adjustment to suit an individual than did Japanese equipment. Ergonomics refers to the holistic usability or utility of an object relative to the morphology of the human body.

These days, we hear people, myself included, refer to ergonomic chairs, or the ergonomics of chairs. It is important that certain relationships, such as seat height off the floor, or the relationship between the seat height and the arm support, be carefully considered when designing a chair. Some chairs, such as the ubiquitous gas-lift office chair have adjustable “everything” in an attempt to make one size fit all.

The ultimate point of all this effort with ergonomics is to make a chair “comfortable”. The problem is that “comfortable” is not so easy to define. Consider the balloon back chair. When these were the height of fashion, they were considered acceptably “comfortable”. The same people also saw whalebone corsets as acceptably comfortable, in the sense that they accepted wearing them despite their discomfort.  Most modern people do not consider either a balloon back chair or a whalebone corset acceptably comfortable at all. The concept of “Comfortable” is subjective at best.

Obviously, the word “Ergonomic” doesn’t not mean the same thing as the word “comfortable”. In fact, a chair can be Ergonomically correct, while still not being a good chair. Let’s consider the ubiquitous gas-lift office chair on wheels again. This chair is fully adjustable and can be adjusted to fit an individual perfectly. Really?

I accept that having the lumbar support adjustable relative to the seat is great, ditto the arm to seat height and the seat to floor height, but a swivel chair on wheels? Let’s unpick this a little.

First, we must simply accept as fact that evolution did not prepare us to sit in chairs for long periods. Sitting is not a natural activity. Sitting cross legged on the floor is probably the most natural way to sit, but I, like most 46 year old Western men, not much care to sit for more than half an hour this way.
Believe it or not, sitting in a chair is an acquired skill. Those people who didn’t mind balloon back chairs all had core strength, and in any case their clothing, especially in the case of women, didn’t allow them to us the back for back support.

We hear sporty people talking about core strength, and long periods sitting in a normal chair has the potential to reduce our core strength. We also hear that extensive sitting changes our skeletal system, causing us to roll our shoulders and for our ribs to slump in.

The concept of active sitting was born to combat some of the negative aspects of chair sitting. Most of you will be familiar with the Pilates ball, a ball that encourages you to “use” your back muscles and to sit with the assistance of core strength. This is great exercise, but there are many down sides to using a Pilates ball for every day sitting activities. The basic concept of active sitting, however, is correct.

Now cut back to the office chair. The chair swivels when you move side to side, locking your body in the one posture. This goes against the very essence of active sitting. In my opinion, the gas-lift chair is ergonomically correct, but the sitting logic is very wrong.
I use wooden seats in most of my armless chairs. This allows you to slide in the seat. If you swivel in the chair, you are changing position and using your core strength. This is not strenuous; quite the opposite. It is less tiring to sit with your “whole body” than to be locked in to a single position for a long period. A simple test of what I mean is the ubiquitous car seat. An expensive car has adjustable “everything” in it’s seat, yet a long drive can still be tiring. Why? It’s because you are essentially locked in to one position the whole time. There is little opportunity to sit actively. Ironically, bigger vehicles such as vans and trucks, are better for long trips precisely because the chairs are generally taller and you can sit more actively.

Let’s get back to the wheels. Are they really a great idea on an office chair? If a chair swivels and rolls, then it is taking away more opportunity for active sitting. A chair with a short rocking motion and a wooden seat will encourage you to sit more actively and ironically be less tiring. If you don’t believe me, drop by our showroom and try out our Tamar or Cataract desk rockers. You will see what I mean in the first 30 seconds.

A surprising number of chair makers give little or no thought to the sitting logic of their chairs. A good chair is a tool for sitting. How it looks, what it is made from, where it comes from are all secondary considerations. The first question should be “does this work as a chair”? If the answer is no, then smile and walk away.

You have been listening to Crafting a Life, the Dunstone Design podcast on all things furniture and woodwork.
I’m Evan Dunstone, and I look forward to your company next time.