A mechanical injury might occur when the baby is in an unusual position at the time of birth (e.x. a breach birth) or when the baby is too large to pass through the birth canal easily.

Caput Succedaneum is a severe swelling of the soft tissues on a baby's scalp that develops as the it travels through the birth canal. It is typically caused by the mechanical trauma of the initial portion of scalp pushing through the narrow cervix. Babies delivered by vacuum extraction are more likely to develop this condition.