In the 1980s SBS took on a more sinister connotation and was used to described physical abuse on an infant whereby the infant is held around the rib cage and shaken violently causing the infant’s head to snap back and forth. The defining symptoms of SBS are stated to be: subdural hematoma, encephalopathy (usually manifest in fatal cases by brain swelling) and retinal hemorrhage. These symptoms are commonly referred to as "the triad." Although there are no accounts of anyone witnessing an infant being shaken in this manner with the resultant triad of symptoms, doctors offered SBS as an explanation for these injuries where there was no apparentimpact injury to the head. For some doctors SBS became not only a possible explanation for the triad of symptoms, but the only explanation.
Over the past three decades thousands of individuals around the world have been charged and convicted of murder/manslaughter/assaults on infants with the mechanism of brain injury defined as SBS. Proponents of the syndrome have attended annual medical conferences on SBS and some have declared themselves to be experts. Doctors have testified on behalf of the prosecution at criminal trials and stated as fact that when the triad of symptoms is present, the only mechanism of injury is SBS. Parents who testified that their child fell and hit his head were disbelieved in the face of the unquestioned expert medical opinion.
At the same time that the SBS experts were testifying in this manner, other doctors and scientists were conducting studies and demonstrating that the mechanism of SBS could not cause the injuries associated with the syndrome. One research study demonstrated that the forces needed to cause a subdural hematoma far exceeded the amount of force that could be generated by shaking.4 The forces generated inside the skull by impact with a rotational component, such as with some falls, are 50 times greater than the forces that can be generated by shaking alone, and still 40 times greater than shaking when the impact is onto a soft surface. Another study determined that impact injuries to an infant’s head did not always result in any injury to the skull or scalp.
Even more compelling are the studies involving documented short distance falls that resulted in the triad of symptoms, with no external head injury. The documentation included falls witnessed by disinterested third parties and falls that were caught on film.These studies all indicate that the triad of symptoms that are said to be the signature of SBS can also result from accidental short distance falls. The biomechanical studies go even further to suggest that the triad of symptoms attributed to SBS cannot be caused by shaking alone. Despite this body of scientific evidence expert SBS doctors continued to testify at criminal trials and routinely denied that the injuries could be caused by anything other than intentional assaultive shaking.