Shaken Baby Syndrome (SBS) has been thought to occur as a result of inertial loading of the head resulting in retinal hemorrhaging, cerebral hemorrhaging, and encephalopathy with little sign of external trauma. However, recent findings suggest that inertial loading alone is not sufficient to cause these symptoms and that cervical trauma will precede head injury. The objective of the current study was to evaluate pediatric neck and head injury potential during purely inertial loading of the head.
Publicly available full-scale vehicle tests and laboratory sled test data from the National Highway Traffic Safety Administration (NHTSA) were analyzed. Each of the tests considered in the current study involved Hybrid III, 3-year-old ATDs seated in age-appropriate, forward-facing child restraint systems in accordance with the manufacturer’s instructions. 131 New Car Assessment Program (NCAP) test reports were reviewed in addition to 32 sled tests. Head Injury Criterion 15 (HIC15) and upper neck peak tension force measurements from the collected technical reports were documented for each of the ATDs (n=228). The collected values were then evaluated in the context of published and accepted Injury Assessment Reference Values (IARVs) for the Hybrid III, 3 year-old ATD.
Of the NCAP tests, 161 (96%) exceeded the upper neck peak tension IARV and 37 (22%) surpassed the HIC15 IARV. Of the 33 data points garnered from the laboratory sled testing reports, 27 (82%) exceeded the upper neck peak tension IARV while only 1 test (3%) surpassed the HIC15 IARV. These data support the hypothesis that inertial loading of the head provides a greater risk of injury to the cervical spine when compared with closed-head injury. The data from the current study indicate that the traditional triad of symptoms associated with infant shaking should be revised to include the presence of neck injury and medical professionals should strive to determine the presence of any neck injury in cases involving suspected shaking.