The objective of this study was to evaluate the thoracic response and injury
metrics of the Hybrid III (HIII-50M) and Test device for Human Occupant
Restraint (THOR-50M) 50th-percentile male Anthropomorphic Test Devices (ATDs)
during frontal, rear-seated sled tests using modern vehicles with various rear
seat characteristics. Test bucks were fabricated from seven vehicles (two
sedans, three midsize sport utility vehicles [SUVs], one SUV, and one minivan)
that represented varying levels of rear seat designs and safety technologies,
e.g., three vehicles had advanced restraints with pretensioners (PT) and load
limiters (LL). Twenty-four frontal sled tests were conducted using three sled
pulses derived from the vehicle-specific New Car Assessment Program (NCAP) crash
pulses (NCAP85 ΔV = 56 kph, Scaled ΔV = 32 kph, and Generic ΔV = 32 kph). The
HIII-50M and THOR-50M ATDs were positioned in the right and left rear seats,
respectively. Maximum chest acceleration (3 ms clip), maximum chest deflection,
and deflection-based thoracic injury risk were quantified for both ATDs. For the
HIII-50M, the maximum chest acceleration was below the injury threshold (60 g)
for all Scaled and Generic tests, but above the threshold during one NCAP85 test
with conventional restraints. The THOR-50M maximum chest acceleration was below
the injury threshold for all tests. The HIII-50M Abbreviated Injury Scale
(AIS)3+ maximum sternum deflection injury risk threshold was exceeded or nearly
exceeded during the NCAP85 tests for three vehicles, none of which had advanced
restraints. The THOR-50M AIS3+ maximum chest deflection injury risk threshold
was exceeded during the NCAP85 test for one vehicle, which had PT and LL.
Although this study indicates that there may be room for improvement with regard
to rear-seat occupant protection, it is currently unknown whether or not either
ATD provides a realistic kinematic response or injury risk prediction in the
rear seat. Future matched postmortem human subjects (PMHS) testing will
facilitate the assessment of the biofidelity and injury risk prediction
capabilities of these ATDs in the rear seat.
