Introduction
A strong ally of engineers! The key to choosing a chair that suits you is the “chair backrest”. Engineers with a ton of desk work cannot avoid long hours of desk work, whether they perform from home or not.
This section describes the adverse effects on the body caused by working in the same posture for a long time and methods for suppressing these adverse effects.

We will also introduce how to choose a chair as deterrent goods and some other useful goods.
What happens if you sit for a long time
It is said that Japanese people spend an overwhelming amount of time sitting and working throughout the day compared to the average value of foreigners.
(The average value of 20 overseas countries is 5 hours, while the average value for Japanese people is about 7 hours. *)
What kind of problems do you have if you keep sitting for a long time?
Swelling of legs
If you sit for a long time, your legs will swell.
There are several reasons for this.
The calf muscles do not work to circulate the blood flow at the tip of the foot, the pressure on the thighs and buttocks impairs the circulation of blood in the surrounding area, and the circulation of lymph is impaired.
These can lead to tiredness and pain as well as thickening of the legs.
As a result, stress is created and it leads to a decrease in concentration, which may interfere with efficient work.
Stiff shoulders and neck
Stagnation of blood flow caused by sitting for a long time also causes stiffness in the shoulders and neck, leading to poor circulation, dizziness, and eye strain.
In addition, since the neck muscles are also connected to the autonomic nerves, symptoms related to the autonomic nerves may occur.
If the autonomic nerves are disturbed, it tends to be difficult to maintain concentration, so this is a point to be aware of for engineers who need to maintain their concentration.
Stress tends to accumulate
If you stay in the same position all the time while sitting, you are more likely to be stressed because you cannot refresh physically and mentally.
When stress builds up, it can affect your daily work, resulting in a decrease in work efficiency.
Points on how to sit without getting tired
Let’s talk about what you need to do to reduce the swelling of your legs and the fatigue and pain of your neck and shoulders caused by sitting for a long time.
Load balance weight
By transferring the weight on the buttocks to the soles of the feet instead of trying to support the body only with the buttocks, and distributing the load to the three points of the buttocks and the left and right soles to support the body. You will not get tired easily.
Also, keep your knees and hips at right angles, straighten your back and sit deep in a chair, and try to pull your chin and place your head on your neck without hanging your head forward while sitting. ..
Since it can reduce the burden on the shoulders and neck, it helps prevent stiffness in the shoulders and neck.

Care for the pelvis by evenly loading the ischium
Another point is the ischium, which is the part where you feel the strongest contact between the chair and the buttocks when you sit on the chair looking for the bone at the bottom of the pelvis called “ischium” and move your body back and forth and left and right.
Sit in a well-balanced and relaxed position so that the force is evenly applied to the ischia on the left and right hips.
This state is the “pelvic upright” posture, and sitting with the pelvis upright leads to pelvic care, and sitting in this posture is also effective for health because it keeps the body in the correct posture.
Types of the chair backrest
Office chairs are categorized into several types by the backrest.
Typical types include low back, middle back, high back, and backrest.
If there is no backrest, it is necessary to support the upper body only with the back muscles and hips, so it is not suitable as an office chair.
At a minimum, a low-back type backrest is required.
Many companies with engineers will use middle-back or high-back chairs, but few workplaces use chairs with headrests.
Low back
A chair with a backrest that is about the height of the waist.
Even though it is the minimum height, the backrest can reduce the burden on the back muscles and lower back.
Also, because it is short, it does not block the view of people sitting around it, and although it is relatively cheap compared to other types of chairs, it is not suitable for sitting with the body supported for a long time.
Middle back
The height of the backrest is between the high back and the low back.
Compared to the high back, it has the advantage of suppressing the feeling of oppression due to the height of the backrest.
On the other hand, it is not suitable for working for a long time, but it is suitable for continuous work for a certain period.
While ensuring more comfort than the low back, the price is lower than the high back, and the number of high-performance models based on ergonomics is increasing, the actual number of products is smaller than that of the low back and high back.
High back
The backrest is large, the height that supports the upper body is high, and the power is strong, so there is an advantage that you will not get tired even if you sit and work for a long time, and there are many high-performance models that pursue further sitting comforts such as with lumbar support and headrest.
This type is indispensable for people who work at home for a long time or who work continuously for several hours or more in the office.
It is large and expensive, and when installed in a room, it feels oppressive.
With headrest
It is a type of chair that has a backrest up to the head and pillow-shaped support on the head.
With a headrest, you can expect to reduce the load on your head and neck by leaving your head on the headrest and fixing it when you work while looking at things at the same distance in the same posture for a long time, such as the screen of a personal computer. increase.
This helps you to sit and work in the correct posture, and also has the advantage of being able to support your head, back, and hips, just like the backrest of a highback.
By using not only the backrest of the chair but also the headrest to balance the weight in the entire chair, you can relax your body, and as a result, you can expect to improve work efficiency and minimize fatigue.
Fixed headrest
The fixed headrest is characterized by its sturdy construction, and you can use it comfortably if you choose one that fits comfortably on your head and has a high cushioning property.
However, there is no way to adjust the height and angle, so it is necessary to check in advance.
Movable headrest
A type of assistive device that provides a means of adjusting the height and angle of the headrest to support the head.
The advantage is that you can freely set the person who is tall or short, the person who has a long neck or short neck, and the angle you like when you put your head on it.
Therefore, when working for a long time with a personal computer, it is easy to keep the distance from the screen constant, which will have a certain effect on suppressing eye and body fatigue.
On the other hand, because of its high functionality, many parts are used and it is fragile, and when the head is placed, the headrest cannot be fixed and it may be difficult to use.
The part of the back that you see
There are several points to consider when choosing a chair that will not get tired even if you sit and work for a long time.
Here, let’s explain the main points of the angle of the backrest and the fabric of the backrest.
Adjusting the angle of the backrest to prevent fatigue
To reduce fatigue even after sitting in a chair for a long time, sit with your pelvis upright.
“Pelvis upright” means sitting in a well-balanced manner with the left and right hips so that the position of the pelvis is where it should be, and sitting perpendicular to the bottom of the chair.
Restoring the pelvis to its original state will be good for the body and effective for maintaining good health.
To sit with your pelvis upright, sit deep in the chair and use the reclining function to adjust the angle of the back of the chair to around 100 degrees.
Backrest fabric
Mesh materials, fabric fabrics, leather, etc. are the main materials used for the backrest.
The mesh is well-ventilated and can be used comfortably in all seasons, and although it looks good, it is preferred, but it has the disadvantage that dust tends to collect between the meshes.
The advantage of fabric is that you can choose various shades due to the nature of the material, so you can choose the color that matches the color tone of the room.
Leather has the advantage of being luxurious and easy to maintain, but it is not suitable for long-term use because it has high adhesion when a person sits down, so it can be said that it is a chair suitable for people who want to stick to the appearance. increase.
Convenient goods
Introducing auxiliary equipment that supports comfortable work when sitting and working for a long time.
Retrofit type backrest
The retrofit-type backrest is a product that helps you work for a long time in a good posture by adding a new chair while using the chair you are currently using.
It is manufactured to match the shape of your back and maintain an S-shaped posture, so it is essential to check in advance whether it fits your back before purchasing.
If you start using it and it doesn’t fit your body, it will put a strain on your body, which may be counterproductive.
Also, it is a good idea to choose a type that can be easily removed from the chair body and washed completely.
cushion
Cushions are goods that support the correct posture regardless of whether the backrest is used or not.
There are many types, such as those that do not get tired even if you sit for a long time by relieving the pressure on the buttocks, and those that fit tightly to the pelvis and prevent body strain, and as a result, help prevent fatigue. You can choose the right one.
summary
For engineers who have a lot of desk work, we explained the adverse effects on the body that occur when working in the same posture for a long time.
I explained how to control this adverse effect on shoulder and neck fatigue, swelling of the legs, and accumulation of stress due to the retention of blood flow.
It is a good idea to help your desk work as much as possible while making use of the goods introduced.