The entire knee joint is a closed cavity, and inside is a negative pressure state, if a small amount of joint fluid, can produce a feeling of swelling. In the process of squatting, the muscles and ligaments around the knee joint are in a state of gradual tension, and the meniscus inside the knee joint is squeezed when squatting. If there is pain at this time, it is likely that the meniscus and ligament damage, depending on the location of the pain suggests that the damage is not the same. If there is pain because of the back side of the knee, it is possible that there is an injury to the posterior horn of the meniscus. If there is pain on the anterior side of the knee and there is some kind of catching sensation, it could be an injury to the cruciate ligament of the knee. Therefore, if you have symptoms, you should not do squatting again, and if the symptoms persist for a long time, it is better to go to the hospital for an MRI to make a clear diagnosis.