When you consider what office chair to buy, there are a few factors you need to consider, particularly when you fall outside the ‘average’ height and stature. Typically, office chairs are designed with the 95th percentile in mind. In simple terms, this means that if you are taller than 6’2” or shorter than 4’11” you would be outside the fit of a standard office chair. This can often make it difficult to find a product to suit you.
With reference to the requirements outlined in the DSE (Display Screen Equipment) Regulations, certain body measurements (known as anthropometric data) should be taken when looking at new office chairs for an office refurbishment, complete office move or upgrading equipment. The purpose of this is to guide an organisation or individual on considering more than ‘just the DSE standards’ when choosing appropriate office furniture to suit their workforce.
The Health and Safety (Display Screen Equipment) Regulations (commonly referred to as the DSE standards) were developed in 1992 and amended in 2002. They state that the following should be considered:
“The work chair shall be stable and allow the operator or user easy freedom of movement and a comfortable position. The seat shall be adjustable in height. The seat back shall be adjustable in both height and tilt. A footrest shall be made available to any operator or user who wishes one.”
The DSE Regulations could be classed as outdated so it is important to consider the latest research alongside them.
Using the three measurements outlined below will make it easy to compare the variation in different members of the workforce. Two people of the same height, for example, may need different seat heights because one has short legs (popliteal height) and a long torso and the other has long legs (popliteal height) and a shorter torso. Therefore, the measurements a business or individual should focus on in choosing office chairs and in trying to accommodate the majority of their workforce are:
Popliteal height (from heel to the back of the knee)
Buttock – Popliteal length (from the back of the buttocks, whilst seated, to the popliteal crease behind the knee).
Hip Width (from one side of the hip to the other, whilst seated).
You would also want to consider the lumbar height on the back of your chair. You should adjust the lumbar curve or backrest height so that it fits into the small of your lower back. A good rule of thumb would be where the top of your trousers or skirt would sit and this should give you a pretty good indication of where your lumbar area is.
Many taller users feel that they need their upper back supported by the chair. From an ergonomics perspective however, as long as your lumbar is fully supported, the rest of your spine will be in the neutral (S-shape) posture. Remember the old typewriter stools where there was a mere cushion fitting into the lower back? Of course, it does vary from person to person and some users may need a chair with a taller backrest, but the focus should really be on the lumbar area.
I would normally only recommend a chair with a high back or headrest for someone suffering with a specific musculoskeletal issue such as whiplash injury or neck and shoulder discomfort where they require additional support.
Whilst these measurements are important to consider, they should not form the complete decision. Many chairs for example don’t meet the appropriate height for the shortest users. This can be accommodated with the use of footrests/sit-stand desks and appropriate workstation setup. Many chairs nowadays will also have a waterfall edge at the front of the chair which creates less impact on the back of the knee for shorter users.
The standard desk height currently is 720mm which correlates to the seated elbow height of a 6’2” male. This means that anybody who is below this height has to adjust themselves to get comfortable at their desk. This is not ideal. There are a couple of ways to accommodate this, namely footrests and sit stand desks.
If you are shorter, you can raise your chair so that your natural elbow height is the same as the top of the desk. What you will notice is that your feet may be dangling. This is where a footrest would help to support the lower body and keep you sitting in your chair comfortably. The other solution could be installing a sit-stand desk as these can typically adjust lower than the standard seated height. You want to aim for a desk that goes down at least to 650mm. This way you can sit with your feet planted on the floor and lower the desk to your natural elbow height to avoid shrugging your shoulders.
A sit-stand desk can also help accommodate taller users because, of course, it can raise in height. But as I mentioned previously, the standard desk height already accommodates a 6’2” male so you would probably have to be taller than this to need to raise your desk height.
Another factor to consider for taller users is the height of the chair gas lift which makes the chair go up and down. By changing this to a taller version you can increase the height adjustment in the chair to accommodate a taller user. This would be a good solution for a tall person who finds their standard chair comfortable, but just too low.
So, there you have it. Some things to consider when looking into office chairs, particularly if you are outside the fit of chairs that are designed with the 95th percentile in mind. In fact, everyone should just consider the above when going through an office chair selection process.
At Osmond Ergonomics, we work closely with our clients to ensure that the optimum solution is provided, and our expert team will ensure that your personal needs are consistently met.
If you would like to discuss or explore your ergonomics requirements further, please contact us online or call 0345 0345 0898 today.