Injury mechanisms in rear seated children aged 9-17 years and the implications for assessing rear seat protection in crash tests

Beck, Ben; Bilston, Lynne; Kazzi, Mark; Brown, Julie

Affiliations

²University of New South Wales, Australia

Abstract

This study examines injury mechanisms among rear seated restrained child occupants between 9 and 17 years of age using in-depth crash investigation. It was intended to determine whether current crash assessment protocols could be improved to better represent non-booster seat using children in the rear seat of cars. Rear seat occupants aged older than 9 years were recruited from 6 major NSW trauma and paediatric hospitals. A detailed review of injury mechanisms, crash and restraint factors and injury outcome was conducted.

The case series consists of 20 occupants aged 9-17 years, 14 were in frontal impacts, 5 in side impact and 1 rear impact. Three occupants used a lap only belt and the remainder used lap sash belts. Thoracolumbar spine, chest and abdominal injuries were the most common injuries in frontal crashes. Head and pelvic injuries featured in side impacts. A neck injury was present in a rear impact case. Thoracolumbar spine injuries were associated with lumbar flexion in combination with submarining; and with axial compression, caused by excessive chest loads. Abdominal and chest injury was associated with belt loading. In side impact, contact with intruding structures was the primary mechanism of injury.

Although this case series is not representative of all rear seated children in crashes, the high proportion of thoracolumbar spine and abdominal injuries observed indicates a need for greater focus on preventing these injuries in older children using the rear seat. During vehicle crash testing, the inclusion of lumbar spine injury measures in dummies would allow for a greater understanding of the effectiveness of safety technologies in the rear seat, as would validated measures of abdominal injury.

Dummy measurements in front seat assessment focus on head, neck, chest and femur loads. While protecting these regions is important for all occupants, this study has demonstrated other body regions that require assessment when addressing rear seat occupant protection. Further the majority of injury in this case series would not be captured using existing front seat dummy protocols.

The results indicate different injury sources for rear occupants than reported for front occupants. Simply extending existing front seat assessment protocols to the rear seat may not adequately assess injury risk for older children in the rear seat.

Links

URL: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv23/23ESV-000392.pdf

Cited Works (15)

Year	Entry
2010	Bilston LE, Du W, Brown J. A matched-cohort analysis of belted front and rear seat occupants in newer and older model vehicles shows that gains in front occupant safety have outpaced gains for rear seat occupants. Accid Anal Prev. November 2010;42(6):1974-1977.
2005	Kuppa S, Saunders J, Fessahaie O. Rear seat occupant protection in frontal crashes. In: Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 6-9, 2005; Washington, DC.
2001	Durbin DR, Arbogast KB, Moll EK. Seat belt syndrome in children: a case report and review of the literature. Pediatr Emerg Care. December 2001;17(6):474-477.
2003	Durbin DR, Elliott MR, Winston FK. Belt-positioning booster seats and reduction in risk of injury among children in vehicle crashes. JAMA. June 4, 2003;289(21):2835-2840.
2007	Bilston LE, Sagar N. Geometry of rear seats and child restraints compared to child anthropometry. Stapp Car Crash J. 2007;51:275-298. SAE 2007-22-0012.
2003	Parenteau C, Viano DC. Field data analysis of rear occupant injuries, I: adults and teenagers. In: Proceedings of the SAE World Congress & Exhibition. March 3-6, 2003; Detroit, MI. Warrendale, PA: Society of Automotive Engineers. SAE 2003-01-0153.
2006	Richards D, Carhart M, Raasch C, Pierce J, Steffey D, Ostarello A. Incidence of thoracic and lumbar spine injuries for restrained occupants in frontal collisions. In: 50th Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). October 16-18, 2006; Chicago, IL.125-139.
2004	Arbogast KB, Durbin DR, Kallan MJ, Winston FK. Evaluation of pediatric use patterns and performance of lap shoulder belt systems in the center rear. In: 48th Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). September 13-15, 2004; Key Biscayne, FL.57-72.
2004	Arbogast KB, Durbin DR, Cornejo RA, Kallan MJ, Winston FK. An evaluation of the effectiveness of forward facing child restraint systems. Accid Anal Prev. 2004;36(4):585-589.
2003	Parenteau C, Viano DC. Field data analysis of rear occupant injuries, II: children, toddlers and infants. In: Proceedings of the SAE World Congress & Exhibition. March 3-6, 2003; Detroit, MI. Warrendale, PA: Society of Automotive Engineers. SAE 2003-01-0154.
2006	Huang S, Reed MP. Comparison of child body dimensions with rear seat geometry. In: Proceedings of the SAE World Congress & Exhibition. April 3-6, 2006; Detroit, MI. Warrendale, PA: Society of Automotive Engineers. SAE 2006-01-1142.
2004	Arbogast KB, Chen I, Nance ML, Durbin DR, Winston FK. Predictors of pediatric abdominal injury risk. Stapp Car Crash J. 2004;48:479-494. SAE 2004-22-0021.
2008	Forman J, Michaelson J, Kent R, Kuppa S, Bostrom O. Occupant restraint in the rear seat: ATD responses to standard and pre-tensioning, force-limiting belt restraints. In: 52nd Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). October 6-8, 2008; San Diego, CA.141-153.
2007	Kent R, Forman J, Parent DP, Kuppa S. Rear seat occupant protection in frontal crashes and its feasibility. In: Proceedings of the 20th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 18-21, 2007; Lyon, France.
1994	Klinich KD, Pritz HB, Beebe MS, Welty KE. Survey of older children in automotive restraints. In: Proceedings of the 38th Stapp Car Crash Conference. October 31–November 2, 1994; Fort Lauderdale, FL. Warrendale, PA: Society of Automotive Engineers:245-264. SAE 942222.