Bones ring when squatting may be caused by the following mechanisms: 1. The presence of abnormal activity of the corresponding joints of the lower extremities, in response to this ringing, the most common is the presence of the corresponding rattles of the knee, hip and ankle joints. In the process of squatting, it may be due to the abnormal activity of the joints in the process of activity, which in turn leads to abnormal ringing, such as the existence of internal joint subluxation, instability, or the existence of meniscus, cartilage, ligament corresponding injury, can cause such abnormal activity, and lead to abnormal ringing. In addition, if there is serious osteoarthritis or free body inside the joint, it will also lead to abnormal sound. 2, may be due to muscle and tendon spasm, for the lower extremity is most common is the lateral knee or thigh muscle spasm, may produce biceps femoris, broad fascia tensor muscle corresponding spasm, and then lead to abnormal activity when the patient squatting, so that the spastic part of the 3. It may be caused by old injury, if there is an old fracture or dislocation, resulting in excessive osteophytes, or if there is joint instability, it will produce a strange sound during squatting.