Many people's daily office furniture only needs a table, a chair, and a computer, and they have to maintain a posture for a long time - sitting. As everyone knows, the hidden dangers of the body also arise from this. How to sit is very knowledgeable.
There is a saying in China that "sitting like a bell" since ancient times. Some people think that the human body is most beneficial to the lumbar and cervical spine only when the back is straight and the spine is firm. This is unscientific.

The correct sitting posture at the desk should be:

When sitting, try to keep the distance between the seat and the desk as close as possible, from the hips to the waist to the back, all close to the seat back, and if necessary, place a cushion between the waist and the seat back; keep the head and neck in a neutral position, and adjust at the same time The height of the seat is so that the desktop is just at the elbow joint when the arms hang down naturally; the knee joint is kept slightly higher than the hip joint, so that the feet can fully touch the ground, and a foot pad can be placed under the desk if necessary.  
 
In this posture, the lower back of the human body is fully supported by the seat back, and the human spine system and its related muscle groups are also fully relaxed, which will naturally feel comfortable and comfortable, not easy to fatigue, and the spine and intervertebral discs are less likely to undergo metamorphosis; The head and neck are in a natural neutral position, without excessive forward flexion and backward extension, so that the cervical spine is kept in a normal physiological arc, and the neck muscles are relaxed to the greatest extent.

Good sitting posture also depends on scientific seats, suitable seats can reduce the harm of prolonged sitting. The height of the chair should be appropriate. If it is too low, the knee will be arched, causing discomfort; if it is too high, the body pressure will be concentrated on the thigh, which will cause pressure on the thigh, and in severe cases, the calf will swell.

The seat surface of the chair should be suitable. If the chair is too narrow, the muscles on both sides of the body will be squeezed and you will feel tired; if the chair is too soft, it is easy to bend the body, and the muscles and bones of the whole body will be unevenly stressed, resulting in back pain.

The back of the work chair should also be exquisite. As long as the activities of the user are not affected, the height of the backrest can be as low as the user's first and second lumbar vertebrae, and as high as the user's scapula and neck. The inclination angle of the backrest is about 110°, and the inclination angle should be gradually increased backward, and its support point for the human body is also gradually shifted upward at the same time.  
 
So how to adjust the height of the ergonomic chair correctly?  
 
Standing in front of a chair, the height of the chair is at the lower edge of the kneecap; sitting on the chair, the inside of the knee is 5 cm away from the front of the chair; the backrest leaves no space under the back; the armrest just touches the elbow

The correct sitting posture, learning to "sit", and a good ergonomic chair are also very important. The ergonomic chair is based on the theory of "ergonomics", summarizes various data in the process of people using computer chairs, and combines modern chair manufacturing technology to develop a chair that is suitable for the correct sitting posture of the human body and can be adjusted for comfort. It can not only meet the needs of people to sit, but also enjoy the comfort and health in the process of "sitting".