The impact of Seatback Loading in Frontal Collisions

Author(s): James Roos, Kevin McClafferty, Dr. Michael Shkrum

Slidedeck Presentation Only (no paper submitted):

4B - Roos


An SUV carrying three occupants was in a head-on frontal collision with a minivan on a two-way, two-lane rural highway. The SUV had broad damage to the front exterior of the vehicle. All occupants received injuries as a result of the collision, but the most severe injuries in the SUV were received by the right rear occupant.

This case investigation aimed to determine the factors and mechanisms responsible for the injuries to the occupants of the case vehicle.

An in-depth collision investigation was conducted by the Motor Vehicle Safety (MOVES) Research Team, as part of a Transport Canada Collision study on restrained rear occupants involved in severe frontal impacts. Information collected and analyzed included observations from the post-collision scene, vehicular damage, occupant injuries, and Event Data Recorder data.

The driver sustained a displaced fracture (AIS-2) of the left clavicle. He had abrasions and contusions on his lower back. The right front occupant had no serious injuries.

The right rear occupant sustained pulmonary contusions (AIS-3), a concussion (AIS-2), small bowel perforations (AIS-2), colonic serosal tears and perforation (AIS-2), right-rectus muscle hematoma (AIS-2), and lacerations on the nose (AIS-1).

The case vehicle was carrying ten large cargo bags at the time of collision. Extensive shifting occurred in the area behind the right rear occupant. There was extensive forward deformation of the right rear occupant’s seatback due to rear loading from the cargo.

The life-threatening abdominal injuries suffered by the right rear occupant were primarily the result of heavy seatbelt loading exacerbated by rear loading. His concussion and facial injuries resulted from contact with the front occupant’s seatback. The driver’s clavicle fracture was due to his torso belt. Superficial skin injuries on his back were from seatback loading due to the rear cargo.

Seatback loading has been typically associated with rear collisions1,2,3. The serious injuries of the rear occupant of this case investigation highlights that cargo shifting is a factor to be considered in frontal collisions involving seatback loading.

1 Dalmotas, Dainius J. Mechanisms of injury to vehicle occupants restrained by three-point seat belts. No. 801311. SAE Technical Paper, 1980.
2 Padmanaban, Jeya, Roger Burnett, and Andrew E. Levitt. Relationship between Seatback Stiffness/Strength and Risk of Serious/Fatal Injury in Rear-Impact Crashes. No. 2009-01-1201. SAE Technical Paper, 2009.
3 Viano, David C. 'Seat properties affecting neck responses in rear crashes: A reason why whiplash has increased.' Traffic injury prevention 4.3 (2003): 214-227.