In fact, the protrusion of the buttocks is not just the bulge of the buttock muscles, but the overall backward bulging of the hip bones (that is, the pelvis), which is in conjunction with the gradual bending of the lumbar vertebrae supporting the pelvis of the body backwards. There is a relationship.

Any woman with normal development has a straight spine when she is a child, so the hip bones have not bulged backwards. Moreover, the child's pelvis is small and the buttocks are poorly developed, so the entire buttocks appear small. But as women age, their lumbar vertebrae gradually bend backwards, so their buttocks also "get bigger." In short, when every woman grows up, her buttocks will protrude backwards. This is a normal physiological development phenomenon and is not surprising. The so-called protrusion means that it protrudes too much than that of ordinary women. If there is this abnormal phenomenon, it is necessary to go to a plastic surgery department to check the curvature of the lumbar vertebrae and correct it in time.