For long hours every day to work at the desk of the office workers, choose a chair that suits you, to protect the spine is crucial. Some people office space is relatively small, they chose a chair without backrest; some people like to adjust the computer chair to the shortest, think so sitting is comfortable; some people do not like hard chair, must sit soft …. This is all right? First look at the chair without backrest. This chair does not have a backrest, people sitting on it lumbar back suspension, so that the load of the lumbar spine greatly increased. For example, an adult weighing 70 kilograms, standing third lumbar spine to withstand about 100 kilograms of weight, but if you sit in a chair without a backrest, the third lumbar spine will be as high as 150 kilograms of weight. It can be seen that there is no backrest chair is most unsuitable for office workers, long-term sitting in this kind of chair, the lumbar spine is more harmful, easy to induce a variety of lumbar spine disease. Too low chair height and table height difference is too much. Long time to sit in this chair against the computer office, will make people’s upper body involuntarily backward, operating the computer arm will be raised, shoulder inward contraction, so it is easy to make the cervical spine, arm and shoulder joints involved, over time will lead to neck and shoulder pain, neck and shoulder spasms, and even dizziness, dizziness and other symptoms. Chair in the end how high is appropriate? Here is a standard, that is, after you sit up, thighs parallel to the ground, knee bend about 90 °, two feet can be stepped on the ground smoothly, at the same time in the operation of the computer, the head and neck in the same vertical line, so that the height of the chair can increase the stability of the body, reduce the degree of spinal involvement. In addition, the height of the backrest also has certain instructions, the backrest is used to support the back of the human body, so its height should be below the shoulders, and in line with the curvature of the human spine curve, slightly tilted backward, so as to allow people to maintain the curve of the spine when sitting. It should be emphasized that even if you choose a very suitable chair for yourself and sit flawlessly, try not to sit for a long time. This is because the pressure on the spine is much higher when a person is sitting than when standing or lying down. So it is recommended that we continue to sit for 30 minutes, then change posture, move the body, such as stretching the upper limbs, shrug shoulders, move the neck, etc., to relieve the pressure on the spine.