Side impact PMHS thoracic response with large-volume air bag

Area of Science:

• Biomechanics
• Injury Biomechanics
• Occupant Protection

Background:

• Side impact crashes remain a significant cause of occupant fatalities.
• Side air bags are a key safety countermeasure, but their effectiveness in diverse populations requires further study.
• Understanding postmortem human subject (PMHS) response is crucial for developing and validating vehicle safety systems.

Purpose of the Study:

• To evaluate the biomechanical response of postmortem human subjects (PMHS) to a large-volume side air bag during a simulated side impact.
• To quantify injury metrics and assess the variability in PMHS response to this specific side impact scenario.

Main Methods:

• Three adult male PMHS underwent right-side lateral impacts at 4.3 m/s against a rigid wall equipped with a deployed side air bag.
• Load cells, a chest band, and triaxial accelerometers measured forces, torso deformation, and acceleration at the head, spine, and sacrum.
• Kinematic data were collected using bone-mounted markers.

Main Results:

• Peak pelvic load was significantly higher (6.8 kN) compared to the shoulder (1.3 kN) and thorax (1.2 kN).
• Lateral chest deflection ranged from 9 to 21 mm.
• Two out of three PMHS sustained rib fractures (2 and 9 fractures respectively).

Conclusions:

• Rib fractures occurred in two subjects despite limited thoracic deflection, highlighting individual variability in injury tolerance.
• Response parameters, excluding fractures, showed low variability, characterizing PMHS response to side air bag deployment.
• These findings contribute to understanding the protective potential and injury risks associated with side air bags in specific impact conditions.