Background: This study aimed to describe the injury mechanism of children's thorax in frontal impact and provide an injury threshold.
Methods: Nine unembalmed cadavers were divided into two groups. A young cohort aged 2 to 4 years (four cadavers) was impacted by a 2.5-kg mass impactor, whereas the older cohort, aged 5-12 years (five cadavers), was impacted by a 3.5-kg mass impactor.
Results: The mean values of peak sternal viscous criterion and accelerations for the older group and younger group were 1.35 ± 0.62 m/s, 81.5 ± 29.2 g and 2.05 ± 0.5 m/s, 65 ± 20.1 g, respectively. The maximum forces in the older group (1138 ± 271.7 N) were significantly higher than those in younger group (776.3 ± 39 N). In seven specimens, injuries after the impact were found.
Conclusions: The full set of cadaveric injuries did not correlate with peak chest deformation, sternal viscous criterion, or peak fourth thoracic vertebra acceleration. However, cadaver thoracic injury showed a strong dependence on dissipated energy to peak deformation.