Case history FD, a 36 week gestation well baby, presented from home after a head injury. During a nappy change, he had been positioned on a changing mat on top of a chest of drawers, one metre above a carpeted floor. He fell off the mat and was found lying on the floor, not losing consciousness.

Developmentally, FD was reported to be a very active baby and parents believed he had ‘wriggled’ off the changing mat. They mentioned that FD had rolled from front to back previously. There was a boggy swelling 5 cm×8 cm in the left parieto-occipital region with no other bruising, injury or abnormality. He was not witnessed to be able to roll during initial assessment.

Safeguarding protocols were followed as the mechanism of injury was not fully explained in a non-mobile infant. CT head revealed a left-sided parietal skull fracture associated with a subdural haematoma. No other parenchymal injury or stigmata of previous traumatic brain injury was seen. There were no retinal haemorrhages, other skeletal survey findings or blood test abnormalities.

During his stay in hospital, the nursing and medical team witnessed (and digitally recorded) FD rolling from back to front: this is available for presentation and corroborated the parents' history.

Discussion Evidence shows that abusive and non-abusive skull fractures are commoner in younger infants and a recent meta-analysis calculated the overall probability that a skull fracture is due to abuse is 29%. Initial consensus opinion in FD's case was that accidental head injury was very unlikely given his developmental age.

This case highlights that normal developmental milestones do not apply to every child. The Denver II developmental screening test, constructed from 2,000 subjects, shows that a baby would not roll before two months. It is crucial in all cases to keep a non-judgemental attitude and be open to mechanisms of injury that seem unusual, particularly if there are Safeguarding concerns.