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Introduction to the concept of ergonomics

The term ergonomics comes from the Greek words ergon (ergon: work) and nomos (nomos: natural laws) and so literally means "natural laws applied to work" or "that which one should do at work". The term has come to refer to the science of understanding human interactions with the environment and how to improve them.

The goal of this scientific discipline is to design and adapt workplace environments and tools to suit the physical and psychological limitations and abilities of human beings. Ergonomic principles can offer useful guidance in the design of workspaces, technical equipment (tools and machinery), work environments and even in organizing the work itself. In the context of office workspaces, for example, working at a computer requires a certain posture that must sometimes be achievable by people of different shapes and sizes. As they offer a variety of sizing options and adjustments, ergonomic office chairs are an adaptive solution to this type of work environment.

Choosing an ergonomic office chair

Office chairs come in a wide range of shapes and prices. One of the basic principals of ergonomics in office chairs is that they should provide total safety. The difference in price between various models can often be attributed to the quality of the components used and the options available. While a good chair does not necessarily have to be expensive, some options and sizing features are essential for the chair to be adaptable to the user and the tasks they perform at work.

Adjusting chair height

Leg length is the determining factor here. To properly adjust the height of the chair, the feet must be flat on the ground with no pressure on the lower thigh. The weight of the body should be evenly distributed among the feet, thighs and buttocks.

Adjusting seat depth

Not all models offer adjustable seat depth. Adjusted seat depth (the distance between the front of the chair and the chair back) ensures proper support for the thighs and prevents circulation from being cut off behind the knees. Optimal seat depth is achieved when you can slip four fingers between the front of the chair and the back of the knees.

Adjusting the backrest

The backrest is adjusted mainly for the purpose of increasing or decreasing support to the lumbar region. This adjustment is essential to maintaining the natural curvature of the spine when leaning on the backrest. During adjustment, it is important to try various positions until the backrest fits perfectly.

Adjusting the tension

When seated, people change positions constantly to keep the blood circulating in the muscles of the thighs and buttocks. On a fixed seat, there is a tendency to slouch, which is bad for the curvature of the back. A chair with adjustable reclining motion offers a greater range of movement to the user. It allows users to change positions from time to time, while maintaining good posture, to lean back while on the phone, reading over a text, or speaking to a co-worker, for example. Apart from the reclining motion itself, the resistance encountered when reclining is an important factor in proper chair adjustment. Reclining tension should be set to prevent the user from falling backward, while allowing the user to recline comfortably and without straining.

Adjusting the armrests

Armrests support the elbows and allow the shoulders to maintain a relaxed posture. Resting the elbows on the armrests rather than on a desk prevents users from leaning forward and placing pressure on the elbows. A good armrest is sufficiently wide and cushioned. Ideally, armrests should be adjusted by width, height and depth (back to front).

In terms of width, armrests should be adjusted according to the width of the shoulders. The user’s arms should be slightly wide of the body, not pressed tightly to either side. Likewise, if the armrests are too far apart, the user may lean to the left or right and sit in a bent position. As for height, the armrests should be adjusted to suit the shape of the user’s shoulders (straight or relatively curved) and arm length. The armrest should support the elbow and part of the forearm when horizontal. Working with hunched shoulders should be avoided. The depth of the armrests should be adjusted to allow the user to sit sufficiently close to the work surface.

Adjusting the headrest

The headrest is of particular importance for users who are often reclined. For regular office work, the headrest is not necessary. The headrest should be adjusted to support the head in a normal, straight position, without pushing the head forward or letting it fall back.