Investigation of pediatric neck response and muscle activation in low-speed frontal impacts.

Pediatric necks present different responses and injury patterns compared with those of adults in motor vehicle crashes (MVCs). To evaluate the effect of different muscle modeling methodologies, three muscle models were developed and simulated under low-speed frontal impact conditions with an average peak acceleration of 3g's. The muscle activation curve for the curve-guided model, the muscle segment was curved using guiding nodes, was further optimized based on experimental data. The pediatric neck model was also simulated under more severe frontal impact conditions with an average peak acceleration of 8g's. Simulation results revealed that the curve-guided model needed more muscle force than the straight-guided model, in which the muscle segment was straight with guiding nodes, and the curve-constrained model, in which the muscle segment was curved without guiding nodes and which imposes more constraints on the head and neck than the curve-guided model. The predicted head responses for the child finite element neck model were within or close to the experimental corridors of 3- and 8-g's frontal impacts. The neck injuries for a 10-year-old child commonly occurred at the interspinous ligament in the C7-T1 segment. The model could be used to analyze the responses and injuries of pediatric neck and head in low-speed frontal impacts.