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Front-Seat Occupant Injuries in Rear Impacts: Analysis of the Seatback Incline Variable in NASS-CDS
Technical Paper
2009-01-1200
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
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Language:
English
Abstract
Objective: This study addresses severe injury risks in rear impacts for front-outboard occupants using the seatback incline variable in NASS-CDS.
Methods: Severe injury risk (MAIS 4+F) was determined for front-seat occupants in rear impacts involving passenger cars from 1995–2006 NASS-CDS data. The risk of severe injury to front-seat occupants was determined as a function of the rotated position of the seatback and crash severity in three delta V ranges: <20, 20–30, >30 mph. The data was also analyzed for newer model vehicles (≥1997 MY) to assess changes with newer seats and head restraints. The effects of seatbelt use, occupant age and BMI (Body Mass Index) were also examined. Individual NASS-CDS electronic cases were also reviewed with MAIS 4+F injury. There were 25 injured occupants in rotated seats and 46 in non-rotated seats.
Results: Severe injury risk for front-seat occupants in rear impacts is lower with a rotated seatback in the most severe rear crashes. For delta V >30 mph, the risk of severe injury was 3.8-times greater when the seat had not rotated rearward (12.26% v 3.20%). For 20–30 mph delta V, the risk of severe injury was similar. In the lower-speed rear crashes the trend reversed, but the sample size was too small and confounding factors made it difficult to draw meaningful conclusions. Seatbelt use lowered the risk for severe injury by 43% in severe rear crashes; obesity and older age increase injury risks. The results of the individual case review shows that intrusion plays a substantial role in determining injury risk by supporting the seat upright or pushing it forward in severe rear impacts.
Conclusions: The relationship between a rotated or non-rotated seatback and injury risk is complex in rear impacts. Analysis of NASS-CDS data finds that a non-rotated seatback increased severe injury risks by 3.8-times for front-seat occupants in >30 mph delta V rear crashes. Analyses of other factors that could explain this increased injury risk other than a non-rotated seat were not suggestive of a cause for this difference other than seat rotation. There remains unanswered the extent to which inaccuracies in the coding of pre- and post-crash seat position may be a factor in some of the findings of this analysis.
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Citation
Edwards, M., Parenteau, C., and Viano, D., "Front-Seat Occupant Injuries in Rear Impacts: Analysis of the Seatback Incline Variable in NASS-CDS," SAE Technical Paper 2009-01-1200, 2009, https://doi.org/10.4271/2009-01-1200.Also In
References
- Anderson JO. Dynamics of Occupants in Automotive Accidents Involving Rear Impacts Report # R-34-1295 Research Laboratories General Motors Corporation April 13 1961
- Burnett R Carter J Roberts V Myers B The influence of seatback characteristics on cervical injury risk in severe rear impacts Accid Anal Prev 36 4 591 601 2004
- Dorofeev S Grant P. Statistics for Real-Life Sample Surveys: Non-Simple-Random Samples and Weighted Data Cambridge University Press 2008
- Mertz HJ Irwin AL Prasad P Biomechanical and Scaling Bases for Frontal and Side Impact Injury Assessment Reference Values SAE 2003-22-0009 , Stapp Car Crash Journal 47 155 188 2003
- Molino L. Determination of Moment-Deflection Characteristics of Automobile Seat Backs. Light Duty Vehicle Division, Office of Crashworthiness Standards National Highway Traffic Safety Administration November 25 1998
- NHTSA Data Collection, Coding, and Editing Manual National Accident Sampling System Crashworthiness Data System USDOT, NCSA 1996
- NHTSA National Automotive Sampling System Crashworthiness Data System 1994–1996 1997
- Partyka SC. Seat Damage and Occupant Injury in Passenger Car Towaway Crashes Office of Vehicle Safety Standards, Rulemaking National Highway Traffic Safety Administration June 8 1992
- Prasad P Kim A Weerappuli DVP Roberts V Schneider D Relationships between passenger-car seatback strength and occupant injury severity in rear-end collisions: field and laboratory studies SAE 973343 , 41 st Stapp Car Crash Conference Society of Automotive Engineers Warrendale, PA 1997
- Saczalski K Burton J Lewis P Friedman, K Saczalski T Study of Seat System Performance Related to Injury of Rear Seated Children and Infants in Rear Impacts Paper No IMECE2002-33517, ASME Intl. Mech. Egr. Congress 2002
- Schwimmer S Wolf RA Preliminary ranking of injury causes in automobile accidents SAE 1961-12-0001, 5th Stapp Car Crash Conference, Association for the Advancement of Automotive Medicine, Des Plaines, Illinois 1961
- Severy DM Brink HM Brink JD Preliminary findings of head support designs. 11 th Stapp Car Crash Conference SAE 670921 , Society of Automotive Engineers, Warrendale PA 1967
- Viano DC The Debate Between Stiff and Yielding Seats: A New Generation of Yielding Seats with High Retention in Rear Crashes SAE Book PT-106 Society of Automotive Engineers Warrendale PA 2003
- Viano DC Parenteau CS Prasad P Burnett R Stiff versus Yielding Seats: Analysis of Matched Rear Impact Tests SAE 2007-01-0708 , Society of Automotive Engineers, Warrendale PA 2007
- Viano DC Role of the Seat in Rear Crash Safety SAE Book Society of Automotive Engineers Warrendale, PA SAE R-317:1-491 2002
- Viano DC Parenteau CS Serious Injury in Very-Low and Very-High Speed Rear Impacts SAE 2008-01-1485 , Society of Automotive Engineers, Warrendale PA 2008a
- Viano DC Parenteau CS Prasad P Burnett R Occupant Responses in High-Speed Rear Crashes: Analysis of Government-Sponsored Tests SAE 2008-01-0188 , Society of Automotive Engineers, Warrendale PA 2008
- Viano DC Parenteau CS Field Accident Data Analysis of 2nd Row Children and Individual Case Review for Safety Priorities SAE 2008-01-1851 , Society of Automotive Engineers, Warrendale PA 2008b
- Viano DC. Seat Design Principles to Reduce Neck Injuries in Rear Impacts Traffic Injury Prevention 9 6 552 560 2008
- Warner CY Strother CE James MB Decker R Occupant Protection in Rear-end collisions: II the role of seatback deformation in injury reduction SAE 912914 , 35 th Stapp Car Crash Conference, Society of Automotive Engineers, Warrendale PA 1991