According to statistics, people currently live and work in a sitting position, generally about 1/3 of the whole day. Or sitting in the office, or sitting to eat, or sitting recreation. Sitting and lying, as well as standing, is an indispensable element of human life “three postures”, the absence of it can not. However, sitting for a long time, sitting for a long time, no matter how healthy people, always have problems, in addition to possible back pain, there is a point can not be ignored, that is, damage to the hip nerve. Sofa, as a popular sitting furniture, its soft and comfortable, refreshing and pleasant enough to fall millions of casual people. However, since the sofa as a sitting device in life, in addition to its advantages, naturally also has its shortcomings. When we use it, we have to avoid the shortcomings of the strengths and weaknesses, there is a precaution. In recent years, the study of human mechanics experts pointed out that: the sofa is too soft, sitting on it, the support of the body’s center of gravity is less stable, users often move their bodies intentionally or unintentionally, to seek a new balance and stability of the body, so long sitting sofa, people will feel back pain, fatigue and weakness, it is difficult to adapt. At the same time, when a person sits on the sofa foot followed the ground, rest for 3 seconds; continue to repeat the leg lift action 20 times. According to the same steps, require the other side of the lower limb for the same leg lifting exercise. Leg lifting exercise to do 20 times for each side of the lower limb as a group, at least 2 times a day, do 1 group in the morning and evening. Can do more better. A few weak people, you can start with 5 -10 times practice, and gradually to the goal of 20 times. If you are consistent, your knee strength and flexibility will improve and your pain will decrease or even disappear.