When a child over 3 years old has a rattling sound when squatting with his legs, he should immediately stop exercising and rest in time, and depending on the cause of the disease, the treatments include medications such as anti-inflammatory drugs and surgical treatments. Children squatting with the cause of the rattle may be physiological popping, may also be the symptoms of other diseases such as meniscus injury. 1. Small children are in the period of physical growth and development, at this time the body’s joints are not stable, easy to physiological popping. In addition, children who do not exercise for a long time, do not do a good job of warming up before exercise, the external environment of the cold will also be popping. Warming up before exercise and practicing a good routine can help relieve the symptoms. 2. Meniscus injuries can be treated with non-surgical treatments, such as immobilization with a joint brace, symptomatic treatment supplemented by physical therapy and rehabilitation exercises to help the injury recover; if the injury is severe, it can be treated with surgical treatments, such as meniscus suture surgery, and so on. In addition, there are other causes of similar symptoms. When a child experiences discomfort, he or she should go to the hospital immediately for a definitive diagnosis and targeted treatment.