Comparison of mechanisms in office chairs-synchronous mechanism, Flextech technology, Smart-Spring technology and others

Classic synchronous mechanism in a rotating chair or the so-called permanent contact mechanism, Flextech mechanics or Smart Spring? When choosing an office chair, you should pay attention to the mechanics, as it affects the comfort and ergonomics of the seat. The heart of any office swivel chair is the mechanism located under the seat. It helps you avoid "sitting mistakes" and encourages active sitting to promote your health. In this way, the mechanism can stimulate movement, support the cardiovascular system and relieve intervertebral discs, that is, the correct mechanism makes the office chair ergonomic and the seat healthier. This article provides an overview and descriptions of various mechnisms in office and swivel chairs. You will learn what function the mechanism performs, how it contributes to healthier sitting, what types and which ones to choose.

Tasks and functions of mechanisms in office chairs

Mechanics is an element that combines all the important components. This means that it accommodates the gas spring and connects the seat to the backrest. Allows you to set controls for adjustment
height, weight adjustment and backrest lock. Their main task is to coordinate the movement of the seat and back and resist the weight of the user. In this way, it determines how you can move in the chair and whether you encourage movement or not. This has a big impact on your health (see the section "healthy sitting through exercise"). There are different types of makhnisms, which may have different names from different manufacturers. Generally, this is usually one of the following types: synchronous mechanics, automatic mechanics, and 3D mechanics. There are other types of mechanisms, but they should no longer be installed in high-quality office chairs. These include permanent contact and rocker arm mechanics. Such office chairs do not affect the user's health. They are often still installed in inexpensive models from large furniture stores and discounters.

Various mechanisms

The six most important types of mechanisms are permanent contact, rocker arm mechanism, synchronization, automatic, 3D mechanics (Flextech) and Smart Spring technology. Below you will find the pros and cons of each of them.

1) permanent contact system
The permanent contact system is a so-called asynchronous mechanism. Asynchronous means that the seat and backrest do not move at the same time, but are separated from each other. When you lean back, only the backrest moves, and the seat stays in place. This sequence of movements creates a " shirt-pulling effect”" The back slides up and down the fabric of the back, pulling the shirt out of the trousers. In addition, the lumbar region loses contact with the back when leaning back. The body has no support, which puts a lot of strain on the back and hips. Today, the permanent contact mechanism can only be found in the low-cost basic segment (IKEA, discounters). Manufacturers of high-quality office chairs still never use asynchronous mechanisms due to their ergonomic shortcomings and low seating comfort.

2) rocker arm mechnism
The rocker arm mechanism works similarly to a rocking chair. The backrest and seat are rigidly connected. This can be seen in the overall design of the backrest and seat. The angle between the seat and the backrest is always the same. Since the upper body cannot open up in this way, there is no healing effect. Only the seat swings on the chair column, which is designed to create a dynamic effect. This mechanism is suitable for guest chairs or conference chairs. You should avoid it with an office swivel chair. Examples are the Vitra Alu chair, Ikea Langfjall / Renberget.

3) synchronous mechanism
The synchronous mechanism is a classic among the mechanisms of high-quality office revolving chairs. For example, it is used in EVERY Interior. When leaning back, a combination of seat and backrest movement occurs. The seat follows the tilt of the backrest in a constant ratio, such as 2: 1 (backrest: 10%, seat: 5% tilt). This mechanic has several advantages. First, the lumbar spine remains optimally supported even in the posterior position, since lordosis maintains contact with the back. Secondly, there is no "shirtless" effect, because the user does not slide up and down the back. Third, this type of mechanism promotes frequent changes in the sitting position and thus promotes healthier sitting.

4) synchronous mechanism of the "autolift"type
The Autolift system is a special form of synchronous mechanism, often called an automaton. Thanks to this mechanism, the user's weight cannot be adjusted separately. The backrest return force is adjusted automatically when seated. The movement sequence is the same as that of a synchronous mechanism, but the comfort level is less, since the back pressure setting cannot be precisely matched to the user's weight. The lever effect cannot be compensated for for light weight people with a long torso, which can reduce the comfort of sitting. This system has an advantage over the synchronous mechanism only if the office chair is used by frequently changing people.

5) Mechanism in Flextech technology
The Flextech mechanism installed in the EVERY Active model is an extension of the synchronous mechanism. It belongs to the category of 3D or 360-degree mechanics. All the features and advantages of the classic synchronous mechanism are combined with greater freedom of movement when sitting. The flexible seating position provides side-to-side and forward movements that mobilize the spine, relieve intervertebral discs, and support the cardiovascular system. According to the Laboratory of Biomechanics of movement at ETH Zurich, the Flextech mechanism provides 4 times more freedom of lateral movement, 3 times more opening of the front seat and 100% more micromotors compared to a synchronous mechanism without Flextech.

6) Smart Spring technology
Smart Spring technology was developed exclusively for the PURE model. This mechanical concept was developed from scratch and is based on dynamic fiberglass polyamide. The Motion Biomechanics Laboratory at the University of Zurich measured greater lateral freedom in the Interstuhl PURE office chair by 26 degrees to the side and an opening angle of 38 degrees when leaning back. When the chair is fully mobile, the user is not restricted in their movements and forced static posture is excluded.In addition to its health benefits, it is extremely easy to use. Adjustment requires only height
seats, the rest adapts to the user's body.

What is the best way to sit while working? Get moving!

Sitting too long can be harmful to your health. The greatest negative impact is caused by too rare changes in the position of the chair. This limits cardiovascular and lymphatic activity. In addition, intervertebral discs, which have a spongy structure, are not supplied with enough minerals.

An office chair mechanism that actively encourages user movement can prevent many problems. Regularly changing the position between anterior, vertical and oblique poses relieves the load on the intervertebral discs and prevents tension.

Thanks to 3D mechanics, continuous micromotors stimulate deep muscles, especially in the pelvis and back.

Moving in an office chair has many positive effects on the user's health. The spine is mobilized by the lateral mobility of the seat, intervertebral discs are removed when tilted back and forth, the cardiovascular system is mobilized and the risk of thrombosis is reduced.

Thus, an office chair with high-quality mechanics contributes significantly to a good feeling in the home office or at work. Healthy and active sitting also supports work efficiency, so the user remains productive throughout the day.

What kind of office chair mechanism is right for you?

Occasionally or for a short time.

The synchronous mechanism or Autolift system is suitable for people who need to do short work while sitting at a desk, but who would like to trust a high-quality and ergonomic office chair. They are also suitable for conference chairs.

A person who works at a desk for many hours

If you use a chair throughout your work day, it may be worth investing in a 3D mechanism so that you can sit actively. We recommend choosing Flextech or Smart Spring technology to improve your health and well-being through frequent posture changes.

A person with complaints of back pain

For people who have back problems, actively sitting or standing is usually the most comfortable and healthy way to do desk work. Therefore, we recommend choosing Interstuhl Pure or Interstuhl EVERY Active chairs.

People who consciously care about their form

Athletes who want to take care of their health and like to spend an active time should rely on Smart Spring technology or Flextech synchronous mechanism.

Multiple people who use the same table together

If several people use the same workplace, the Smart Spring system in the Interstuhl PURE chair is a good option. Here, the lamp deflection force is adjusted automatically, so not everyone needs to change the setting.