Sudden leg clenching in girls is commonly seen in leg clenching syndrome, which falls within the range of childhood behavior disorders, mostly occurring between the ages of 1-3. Generally, most girls’ leg clenching symptoms will subside as they grow older. Girls of other ages may also experience sudden leg clenching, but the cause is not yet clear, and may be related to local stimulation, sexual organ development, emotional disorders and other factors: 1, local stimulation: wearing too tight shorts, vaginal foreign body stimulation, and the local presence of vaginitis, urethritis, eczema, pinworm disease and other factors, physical or inflammatory factors can stimulate the genitals, causing itching and other discomfort, thus causing girls sudden 2, the development of sexual organs: puberty is also an important period of sexual development, girls will develop curiosity and try to act, which will cause the symptoms of sudden leg clenching; 3, emotional disorders: long-term monotonous environment, activity behavior is restricted, lack of parental attention may also be through the leg clenching, to relieve the emotional unsatisfied situation; 4, other: developmental delay, neurological abnormalities, endocrine disorders, such as calcium deficiency, endocrine disorders. Endocrine disorders, such as calcium deficiency leading to increased neuroexcitability, as well as poor sex education may also lead to sudden leg clenching of girls. Girls with sudden leg clenching can first check whether there is clothing discomfort, and timely medical examination to exclude infections and other disease factors. Parents do not have to be overly nervous, and should not use a strong attitude to correct, should be supported and understood, and the correct guidance. In addition, sudden leg clenching in girls may also be related to seizures, if accompanied by general convulsions, impaired consciousness and other symptoms, you need to go to the hospital to check whether there is traumatic brain injury, tumors, central nervous development abnormalities and other conditions.