Task chairs

What's so special about Task chairs?

Ergonomic furniture is an essential element of the contemporary office. A checklist of features which determine whether or not a chair is an ergonomic chair and safe enough to allow people to sit in it for extended lengths of time first emerged in the late 1980s and has continued to expand. These features vary from institution to institution and country to country, but some common elements are:
 
- Height and depth adjustable armrests
- Height and depth adjustable seats
- Height adjustable lumbar support
- Large, quintuple bases for stability

The adjustable features are required to accommodate varying body sizes, but all these extra features and additional mechanisms tend to make office chairs more robust, and have contributed gradual increase in size of the office chair over the last twenty years.

That is why a professionally designed office chair should:

•    guarantee that the vertebral column of a seated person will be allowed to retain its S-shape
•    provide the muscles of the back with reliable support
•    reduce the pressure on the lumbar region of the spine by giving the torso stability
•    be upholstered in such a way that the muscles of the pelvis and thighs are not subjected to undue stress and
•    ensure that, thanks to a carefully equilibrated suspension, there will be no unexpected jolts – especially when somebody is in the act of sitting down.

Usually, a good task chair will have the following components:

1)    Headrest

Headrests are a great help in taking the strain off neck and shoulder muscles, particularly in a very relaxed posture, and contribute to unhindered breathing. A precondition is easy adjustment options in a horizontal and vertical direction that allow an exact adaptation to the size of the user and relevant posture.
They are fairly uncommon features in office chairs, and tend to be employed either to distinguish a chair as executive seating or for ergonomic purposes. At times the structural elements of the headrest are used in conjunction with movement or adjustment mechanisms.

2)    Back rest

This is a key component of the office chair and they have undergone an extensive evolution. It should follow the movements of the body, giving it the necessary support in every position and helping it return from relaxed to an upright posture.
There are various methods of cushioning and diverse supporting structures that have been used in back rests. Each cushioning technique has been explored by manufacturers in a seemingly endless variation, using a wide spectrum of materials.

3)    Armrest

Armrests appear on most office chairs and they have undergone an extensive evolution. Armrests are generally located close to the seat, back rest and seat-stem joinery, so there are many ways in which they can be attached to the chair.

4)    Lumbar support

Lower back support is most commonly referred to as lumbar support. A few chairs provide support to the sacral or thoracic region of the back, but it is very important for persons who sit use the task chair for a long period of time.

The lumbar support is correctly adjusted if the back is supported at the transition from the pelvis to the spine and the back rest offers the back support in a relaxed, upright posture without exerting any noticeable pressure on the spine.

5)    Seat

Chairs with seat depth adjustment allow people of all sizes to adjust the distance between to their needs, in this way combining maximum seating comfort and an optimum support function on the back rest.
The elements that join the seat and stem of office chairs range from static parts to more complex kinetic mechanisms, which allow the chair to recline.

6)     Base

A base is used in all office chair designs and is a defining element of chair construction. The bases can be platform, triple, quadruple and quintuple structures and some of them use a footrest.