Squatting if the posture is not correct or too long will hurt the knee, if the posture is correct and squatting time is not long, generally will not hurt the knee. Before doing squatting, you should do a good job of relaxing the whole body, avoiding muscle tension around the knee joints, incoordination and so on will cause the knee force to increase, resulting in knee injuries. In addition, when squatting, we should pay attention to the posture to avoid knee inversion and outversion, knee inversion and outversion will increase the knee cartilage force, cause wear and tear caused by knee injury. In squatting time and frequency should also be limited, squatting time is longer, too much frequency, the knee joints to withstand the greater the pressure, the pressure of nature will increase the wear and tear of the knee joints resulting in knee injuries. Reasonable squatting training, in addition to the knee force increase, in addition can also enhance the muscle strength around the knee joint, help to maintain the stability of the knee joint, thus to a certain extent on the knee joint has a protective effect.