Analysis of pregnant occupant crash exposure and the potential effectiveness of four-point seatbelts in far side crashes

Duma, Stefan M.; Moorcroft, David M.; Gabler, Hampton C.; Manoogian, Sarah M.; Stitzel, Joel D.; Duma, Greg G.

Affiliations

¹Virginia Tech – Wake Forest, Center for Injury Biomechanics, Blacksburg, VA

Abstract

The purpose of this paper is to present the crash exposure patterns of pregnant occupants and to evaluate the effectiveness of restraint systems, including four-point seatbelts, in far side crashes. The NASS CDS database revealed that 53.0 % of pregnant occupants are exposed to frontal crashes while 13.5 % are exposed to far side impacts. Given that far side crashes were the second leading crash mode after frontal impacts, a previously validated MADYMO computer model of a 30 week pregnant occupant was utilized to investigate pregnant occupant biomechanics in far side crashes. Three impact speeds (5, 15, and 25 mph) were simulated with four restraint conditions: unbelted, lap-belt only, three-point belt, and a four-point belt. Direct abdominal contact from the shoulder strap of the three-point or four-point belt caused uterine-placental strain in contrast to the inertial loading induced strain in the lap-belt and unbelted cases. Overall, the three-point and four-point belt systems provide superior restraint effectiveness for the pregnant occupant compared to the lap-belt and no restraint cases. The four-point resulted in slightly better performance than the three-point belt by reducing the fetal injury risk and occupant excursion.

Cited Works (5)

Year	Entry
2003	Moorcroft DM, Stitzel JD, Duma GG, Duma SM. Computational model of the pregnant occupant: predicting the risk of injury in automobile crashes. Am J Obstet Gynecol. August 2003;189(2):540-544.
2001	Rupp JD, Klinich KD, Moss S, Zhou J, Pearlman MD, Schneider LW. Development and testing of a prototype pregnant abdomen for the small-female Hybrid III ATD. Stapp Car Crash J. 2001;45:61-78. SAE 2001-22-0003.
2001	Hardy WN, Schneider LW, Rouhana SW. Abdominal impact response to rigid-bar, seatbelt, and airbag loading. Stapp Car Crash J. 2001;45:1-32. SAE 2001-22-0001.
2002	Weiss HB, Strotmeyer S. Characteristics of pregnant women in motor vehicle crashes. Inj Prev. September 2002;8(3):207-210.
2004	Duma SM, Moorcroft DM, Stitzel JD, Duma GG. Evaluating pregnant occupant restraints: the effect of local uterine compression on the risk of fetal injury. In: 48th Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). September 13-15, 2004; Key Biscayne, FL.103-114.

Cited By (5)

Year	Entry
2007	Manoogian SJ, Duma SM, Moorcroft DM. Pregnant occupant injury risk using computer simulations with NCAP vehicle crash test data. In: Proceedings of the 20th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 18-21, 2007; Lyon, France.
2008	Manoogian SJ, McNally C, Stitzel JD, Duma SM. Dynamic biaxial tissue properties of pregnant porcine uterine tissue. Stapp Car Crash J. 2008;52:167-185. SAE 2008-22-0007.
2008	Manoogian SJ. Protecting the Pregnant Occupant: Dynamic Material Properties of Uterus and Placenta [PhD thesis]. Virginia Polytechnic Institute and State University; May 29, 2008.
2012	Alphonse VD. Injury Biomechanics of the Human Eye During Blunt and Blast Loading [Master's thesis]. Virginia Polytechnic Institute and State University; March 26, 2012.
2013	Kusano KD. Methodology for Determining Crash and Injury Reduction from Emerging Crash Prevention Systems in the U.S. [PhD thesis]. Virginia Polytechnic Institute and State University; 2013.