Out of position (crash testing) explained

Out of position (OOP), in crash testing and car accident medical literature, indicates a passenger position which is not the normal upright and forward-facing position.^[1] For example, a common case observed in crashes is the position of an occupant when reaching for the car radio,^[2] or panic braking in unbelted passengers.^[3] The concept is of interest because small changes in a passenger's position can have profound effects on the actual kinematic response, especially in rear impacts, as shown both in practical testing and theoretical models.^[1]

Risk of injury

Out of position occupants are at increased risk of injury. Even low speed impacts can cause disc herniation and lumbar fracture on OOP passengers.^[2] Airbags can prove fatal on OOP passengers:^{[4] [5] [6]} modulating the airbag folding pattern has been proposed as a method to reduce injuries.^[7] Crash testing has shown increased forces acting on the neck and torso when dummies were leaning forward and not upright; a partial correlation with the seat stiffness has been observed, with stiffer seats increasing the force loads on the upper neck.^[8]

External Weblinks

• U.S. FMVSS 208 Test Configurations

Notes and References

1. Book: Stephen M. Foreman. Arthur C. Croft. Whiplash Injuries: The Cervical Acceleration/Deceleration Syndrome. 8 December 2012. 2002. Lippincott Williams & Wilkins. 978-0-7817-2681-8. 104–.
2. Book: Larry S. Nordhoff. Motor Vehicle Collision Injuries: Biomechanics, Diagnosis, And Management. 8 December 2012. 2005. Jones & Bartlett Learning. 978-0-7637-3335-3. 513–.
3. Book: Society of Automotive Engineers. Air bags and belt restraints. 8 December 2012. 1 March 2004. Society of Automotive Engineers. 978-0-7680-1412-9.
4. Book: Michael Griebel. Marc A. Schweitzer. Meshfree Methods for Partial Differential Equations. 8 December 2012. 2003. Springer. 978-3-540-43891-5. 249–.
5. Book: Hans-Joachim Bungartz. Michael Schäfer. Fluid-Structure Interaction: Modelling, Simulation, Optimisation. 12 December 2012. 14 September 2006. Springer. 978-3-540-34595-4. 101–.
6. Book: Mary Roach. Stiff: The Curious Lives of Human Cadavers. 12 December 2012. 17 May 2004. W. W. Norton & Company. 978-0-393-32482-2. 93–.
7. Malczyk. A. Adomeit, H-D. THE AIRBAG FOLDING PATTERN AS A MEANS FOR INJURY REDUCTION OF OUT-OF-POSITION OCCUPANTS. Proceedings of the 39th Stapp Car Crash Conference, November 8-10, 1995, San Diego, California, USA (SAE Technical Paper 952704). 1995. 19035. 7 December 2012.
8. Benson. B.R.. Smith GC . Kent RW . Monson CR . EFFECT OF SEAT STIFFNESS IN OUT-OF-POSITION OCCUPANT RESPONSE IN REAR-END COLLISIONS. Proceedings of the 40th Stapp Car Crash Conference, November 4-6, 1996, Albuquerque, New Mexico, USA (SAE Technical Paper 962434). November 1996. 331–44.