Giampiero Soccorso, a consultant paediatric surgeon, said Kaylee-Jayde Priest had suffered "widespread" injuries in the abdomen and the chest.
The three-year-old was found dead at a flat where she lived with her mother in Kingshurst, on August 9 last year, a court had previously heard.
Kaylee-Jayde Priest's mother Nicola Priest, 22, from Edgbaston, and Callum Redfern, 21, from Dudley, both deny murder and other charges.
Mr Soccorso said there were injuries to the girl's abdominal wall, pancreas and haemorrhagic bruising or bleeding to the transverse colon, a trial heard.
And there was further haemorrhagic bruising or bleeding in a part of the small bowel alongside other injuries to the abdominal region, jurors were told.
Birmingham Crown Court was told that there were "recent fractures" to Kaylee-Jayde's left sixth and seventh ribs, with the sixth rib being dislocated.
The "rough edge" of it had come into contact with the left lung which caused air to "leak" out of it into a space between the lung and chest wall, a judge heard.
Mr Soccorso, who is based at Birmingham Children's Hospital, said the pneumothorax, or collapsed lung, occurred due to the "accumulation of air" in the area.
It added more pressure on the lung each time Kaylee-Jayde breathed in, which led to the lung collapsing due to air continuing to leak out of the lung, jurors heard.
The expert said there was also a "shift" of the rest of the organs in the chest towards the right-hand side because of the substantial pressure in the left-hand side.
Mr Soccorso, questioned by prosecutor Mr Andrew Smith QC on what type of accident could explain the injuries, suggested a road traffic accident where a toddler is hit by a car going "at least at 40mph" or a child falling from a third floor of a building and landing on a hard surface.
The expert told the court a fracture injury to a child's ribs of the age Kaylee-Jayde was is "more unusual" than an abdominal injury and said there must have been a "very high" degree of force involved, jurors heard.
Mr Soccorso said he had only seen something similar in one case during his experience – where a child had suffered similar injuries – and that was where a child had been "kicked by a horse".
The consultant paediatric surgeon, who said the injuries could have been caused alternatively by punches and kicks, said there must have been "more than one" when questioned if the injuries could've been inflicted in a single blow by prosecutor Mr Andrew Smith QC.
Mr Soccorso, when questioned why he came to that conclusion and whether there was a minimum number of punches or kicks required to cause the injury, said the injuries were "widespread" in the abdomen and chest and there would have to be "several" punches and kicks to cause the injuries.
Nicola Priest, of Poplar Avenue in Edgbaston, Birmingham, and Callum Redfern, of Temple Street in Dudley, deny murder and a separate alternative charge of manslaughter.
They are also accused of causing or allowing the death of a child and cruelty to a child, between June 12 and August 3 last year. They deny all charges.
The trial continues.