Emily has taken up her position for birth perhaps a month or only days in advance. She may achieve this position by making small stepping movements and to push her feet off a the firm wall of the uterus. As her feet push, her head becomes well lodged in the exit and she cannot get out. This is her engagement for birth. `When her head becomes engaged in the cervix, her mother will feel the "lightening" as the mass of the baby sinks lower.