As a company employee,you may have to work for at least 35 years from 20 to 60,you may have to spend 11 and a half years in your ergonomic office chair. This is unbelievable,right. That is the truth.

So it is a commonsense that buying a good ergonomic office desk chair for yourself absolutely worth the investment, the ergonomic desk office chair is equivalent as your second bed along with you the whole life .

However, the money has to be spent clearly, There are a number of key factors to consider when you’re deciding what office desk chair to buy,In this article, we’ll take a look at five vital points in any office chair purchasing decision

1. Sitting posture.

In the office, people usually use three kinds of sitting positions, that is, forward-leaning posture, upright position and backward position:
If the effect of sitting posture on eyesight is ignored, the forces on the three sitting positions are different:
The forward-tilting sitting position is the sitting position used by most people at work, but this sitting position will actively pull the muscles of the back, and the physiological bending of the lumbar vertebrae protruding forward will also be straightened artificially. Patients with lumbar discs will obviously feel the problem of this sitting position.

Sitting upright position is generally considered to be a more correct sitting position, but in fact, there are also problems. It is mainly to straighten the body, which will make the whole spine in a taut state. In fact, it will not last long.
Sitting on the back is relatively scientific, especially with the help of a suitable seat, the back and seat of the chair can bear part of the weight of the body and reduce the load on the spine and ischial tubercle. Even the ergonomically designed seat back can bring the spine close to the natural state. In addition, the angle of leaning back is not fixed, generally speaking, it should be about 100 degrees.

2.Body pressure.

When sitting, the body pressure of the cushion part is mainly concentrated in the ischial tubercle, if the cushion design is not suitable, the contact between the knee fossa and the leading edge of the cushion will also have a certain pressure. The body pressure distribution on the back of the chair is mainly concentrated in the waist cone and shoulder blades, so you can try to feel it by yourself. Generally speaking, the pressure on the back is less than that on the buttocks. Pay attention to the seat pressure distribution shown below:

Just talked about some preliminary ergonomic principles, now let's talk about the choice of each part of the office seat, starting with the headrest.

3. Headrest.

Not every chair needs a headrest, but if you sit for a long time, you need a headrest. It has been said above that the scientific sitting position is the back position, when you lean back, if you do not have a headrest to support your 4-6 kg head, then your fragile cervical vertebra will become a problem, because many people do not have a headrest. May inadvertently rest to one side at work (usually on the right).
There may be no need for a chair with a head pillow in a place like a conference room, but your office chair should have a headrest, especially during the lunch break, which is essential if there is no recliner.

4.Backrest.

According to the body pressure distribution mentioned above, the backrest mainly bears the pressure of the scapula and the lumbar spine, so the backrest should be divided into two parts, namely, shoulder and lumbar. The material should be breathable and can keep the supporting back from deformation to avoid spinal curvature and muscle fatigue.
Due to the different height and posture of each person, the integrated ergonomic back can not be personalized for everyone. In the case of sitting back, most ergonomic chair have a suitable shoulder but uncomfortable lumbar, or the user's tail vertebrae are required to sit close to the back of the chair in order to achieve better results.
Therefore, generally speaking, if the backrest is divided into two parts: the lumbar and the back, it is more practical to adjust independently. There are also designs that further decompose the back and waist into left and right, which is useful when the user twists and sits to one side.

5.Backrest tilting

Some studies have shown that sitting back with a backrest titling of about 100-135 degrees is fine, but if you consider taking a lunch break in an mesh ergonomic chair, the bigger tilting angle you could get, the better until you lie flat at 180 degrees. 

6. Seat cushion.

1. Seat cushion and seat pressure.
The cushion is the component that bears the largest weight in the whole ergonomic task chair, and as mentioned earlier, the main weight is concentrated in the ischial tubercle, so the cushion material should be soft and breathable, and the leather or leather surface, sponge lining and plywood bottom are relatively common combinations. but leather is not wear-resistant, sponge elasticity is limited, plywood is not durable and other problems are also common. High-end ergonomic chair products usually use  mesh  that is, breathable and soft.

2. Seat cushion and sitting height.

In addition to the ischial tubercle, another place with heavy body pressure is the thigh. If the seat cushion is higher, causing the legs to fall below the ground, it will also form a certain degree of pressure in the knee fossa, and sitting for a long time will lead to numbness. If the user's legs cannot touch the ground, the thighs will put more pressure on the chair surface:
Therefore, the seat cushion needs to be able to adjust up and down. Some people have done some research: the knee socket is about 2cm higher than the seat cushion, which is more comfortable.

7.Seatpad

Seat size is mainly seat width and seat depth, seat width should be as wide as possible, but seat depth should be moderate, too deep will cause people to sit in the front half, backrest loses its function, too shallow will make the front of the thigh suspended, and the weight will be borne by too much of the calf.
Therefore, if the seat surface can be adjusted back and forth, the control protruding outward or withdrawing inward is a more practical design.

8.Armrest 

the armrest of the ergonomic computer chair is also indispensable, mainly when sitting in a casual posture, the arms have something to rely on, and the armrest can also help people get up quickly. Armrest are generally not designed too high to avoid shrugging, so adjustable height and rotatable armrest are not very practical.

9.Gaslift and base.

1. Gaslift.

In order to ensure safety, do not buy cheap ergonomic chairs , if you do not know how the quality of your chair, then you should pay attention to, first, do not frequently rise and fall, second, do not twist the cylinder (for example, often against the front seat), in addition, it is usually best to put the seat at the bottom, when the air pressure on the gaslift is downward, not easy to be pushed out.

2. Base.

Look for a 5-star base which has been proven to be the safest and easiest to move around. Metal (aluminium) chair bases are stronger for heavier people (over 125 kg), but are mostly on chairs for aesthetics.

Most chairs have twin wheel plastic castors for movement. Some chairs have soft castor options which are ideal for timber or tiled floors. The plastic is softer to prevent scratching and scuffing floors, and the castors use more friction to stop the chair from sliding out from under you.

Task chairs have a gas lift to raise the chair height (typically 125-135 mm in height). You should be able to raise the height of the chair so the front of your knees are level (or slightly below level) with your thighs and your feet are firmly on the ground. Some chairs have a 80mm gas lift for smaller people or 200mm gas lift for taller people