In the previous post Ergonomics in the office we discussed the meaning of ergonomics and the benefits that an ergonomic office can offer.
In this post we will instead analyze what ergonomic office chair means and how to choose one.
An office chair must offer a set of adjustments that enable to find a comfortable seating position to the most possible users.
The fact that a chair is comfortable for you is a subjective evaluation, related to some of your physical parameters, and primarily the stature.
But this office chair can only be defined as ergonomic if a scientific study has been conduced proving its comfort for the 90% of possible users.
Scientific means among other things that it is necessary to identify an adequate sample of users who will test the chair (of different heights in order to represent the 90% of possible users), and that the collection and analysis of data must be carried out according to the scientific method.
Alternatively, the manufacturers and the scientific community promoted a series of studies which bring to the concept of Normative.
The Normative (Standard) is a set of rules respecting which an office chair can be defined ergonomic and suitable for the office usage, that is for a continuous use of 8 hours a day.
For Office chairs on the European market there is the EN1335 Standard which provides a series of dimensional requirements to guarantee the ergonomics of the chair.
Respecting these dimensions and these adjustments, it is as if the chair had been subjected to the scientific study of which we spoke above.
For example, the standard states that the chair lumbar support must have an adjustable height from 6.69 in to 8,66 in with respect to the seat. This means that all users who will seat on that chair, from the smallest to the largest of users, in 90% of cases will be able to adjust the support in a comfortable position.
And so also for the seat, for the mechanism and for the armrests, specific regulation ranges are stated by the Normative.
In addition to the ergonomic aspect, the Standard also provides load and fatigue tests on the chair, so that it is also robust and durable, suitable for continuous use.
There are several accredited laboratories to certify the product correspondence with respect to the Normative.
For example in Italy CATAS, of which SbS is a member, can certify the product compliance with respect to the EN1335 Standard.
SbS chair kits are almost entirely tested according to this Standard, both at the internal test Lab (especially during the product design phase) and at CATAS for an official certification.
The answer is BAASICALLY NO.
That is, an office chair tested in Europe according to the EN1335 standard can be defined as ergonomic.
Conversely, an untested chair can only be defined as ergonomic if it is comes with a scientific study with the assumptions we have discussed before.
So pay attention to all office chairs that are declared ergonomic: we check that it is EN 1335 certified or that it comes with an ergonomic study as an alternative.
Some high-end products on the market in addition to passing the test required by the standard are subject to further scientific studies.
These studies normally concern functions not foreseen by the Standard, for superior comfort and therefore better ergonomics.
For example there are studies on the adjustment (as well as in height) also in depth of the lumbar support, or studies on the forward tilt (forward tilt of the seat) or even studies on the asymmetrical lumbar support that demonstrate the ergonomic improvement related to these additional features.
We hear more and more often about ergonomics and ergonomic products. It is a lively issue but sometimes people talk about it inappropriately. In this short article we would like to answer some simple questions, and in particular: What does ergonomic mean? Why is a product ergonomic or not? Regarding an office environment, what does […]