Ligament laxity is related to congenital diseases, prolonged exercise and acquired trauma. Congenital diseases such as neuromuscular disease and genetic factors related to congenital muscle ligament laxity, the patient is mostly manifested in walking unsteady, easy to fall. Regular exercise groups such as dancers, contortionists, etc., ligament stretching exercise for a long time, will be looser than normal people, joint activities significantly beyond the normal range. Acquired ligament laxity is mostly related to trauma, ligament rupture or partial rupture without surgical repair, the phenomenon of laxity will occur after healing, manifested as more than the normal state of laxity, ligament laxity will reduce the bondage to the joints to increase the gap between the joints, easy to cause premature degeneration of the joints. There are many other causes of ligament laxity, if the symptoms of ligament laxity, it is recommended that the patient go to the hospital, to clarify the cause of the disease, and receive regular treatment.