Rib and sternum fracture risks for restrained occupants in frontal car crashes

Area of Science:

• Traffic Safety Research
• Biomechanics
• Injury Prevention

Background:

• Frontal car crashes are a leading cause of occupant fatalities, with the thorax being the most vulnerable region.
• Understanding injury mechanisms and risk factors is crucial for improving vehicle safety standards.

Purpose of the Study:

• To quantify the relationship between risk factors (speed, age) and the probability of rib and sternum fractures in frontal crashes.
• To assess if rib fractures can predict sternum fractures in car occupants.

Main Methods:

• Utilized weighted German crash data from 1999-2021 to develop injury risk curves.
• Analyzed contingency tables to calculate fracture prediction accuracy (sensitivity, specificity, precision).

Main Results:

• Elderly occupants (≥65 years) showed increased risk for both rib and sternum fractures.
• Delta-V (change in velocity) and occupant age were significant predictors; sex was sometimes significant.
• Sternum fractures were more frequent than rib fractures and often occurred independently.
• Female occupants had a higher risk of combined rib and sternum fractures and isolated sternum fractures.

Conclusions:

• Elderly and female occupants require targeted thoracic injury criteria for enhanced frontal crash protection.
• Rib and sternum fractures are not reliably associated, indicating the need for separate prediction and evaluation models for sternum injuries.