Professor Risdon, who works at Great Ormond Street hospital and is Britain's foremost paediatric pathologist, had examined Mia's body two years ago and concluded that the rib fractures were "extremely unlikely" to be the result of resuscitation.
At the time, he had never come across broken ribs in infants caused by attempted life-saving. Then, two weeks after the trial started, he wrote to the judge saying he had found evidence of rib fractures caused by resuscitation in three children he had examined in the previous month alone.
Professor Risdon said Aimee had suffered damage to her lumber cord, which was also consistent with her being shaken.
He said he did not think the three fractured ribs, bruising and bleeding to the abdominal wall, were caused when doctors at Basildon Hospital fought to save Aimee's life and they were likely to have been caused by a "kick or a punch."