Rattling of joints upon movement may be caused by physiological reasons, ligament laxity, abnormal joint structure and other factors. 1. Physiological reasons: if the patient is usually in a static state, when the flexion and extension movements or the body is suddenly pulled by external forces, there may be a situation where the joints rattle with every movement, which may be due to the sound of rupture of air bubbles squeezed inside the joint cavities, and generally not combined with pain, which is a physiological phenomenon. 2. Ligament laxity: when the patient after strenuous exercise, will easily lead to ligament damage, causing degeneration, laxity and other phenomena. During activities, the joints will be prone to rattling when they move. 3. Abnormal joint structure: If long-term strain, it may lead to changes in the joint structure, such as cartilage wear, knee meniscus injury, etc., because of friction and the phenomenon of ringing. If you have a joint that rattles when you move, and if you have a combination of discomforts, you should consult a doctor in time to clarify the cause of the disease and follow the doctor’s instructions for treatment.