The causes of crooked buttocks are as follows: 1. It may be caused by scoliosis, especially scoliosis of the lumbar vertebrae, which may lead to tilting and bending of the entire lumbar, sacrococcygeal and hip clefts. 2. It may be caused by hip contracture or simple muscle tension or spasm of the hip, which may manifest as tilting of the hip cleft. When this occurs, it will also be accompanied by abnormalities in walking of the lower limbs, such as the inability to bring the legs together while standing, or walking with a more pronounced ectopia. Regardless of the cause of the crooked buttock cleft, it is best for the patient to actively go to a regular hospital and ask an orthopedic surgeon to conduct relevant examinations and, if necessary, cooperate with auxiliary examinations to promptly rule out relevant diseases and give reasonable treatment.