Out of position (OOP), in

crash test A crash test is a form of destructive testing usually performed in order to ensure safe design standards in crashworthiness and crash compatibility for various modes of transportation (see automobile safety) or related systems and componen ...

ing and car accident medical literature, indicates a

passenger A passenger (also abbreviated as pax) is a person who travels in a vehicle, but does not bear any responsibility for the tasks required for that vehicle to arrive at its destination or otherwise operate the vehicle, and is not a steward. The ...

position which is not the normal upright and forward-facing position. For example, a common case observed in crashes is the position of an occupant when reaching for the

car radio Vehicle audio is equipment installed in a car or other vehicle to provide in-car entertainment and information for the vehicle occupants. Until the 1950s it consisted of a simple AM radio. Additions since then have included FM radio (1952), 8-t ...

, or panic braking in unbelted passengers. 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. V08650P003

Risk of injury

Out of position occupants are at increased risk of injury. Even low speed impacts can cause

disc herniation Spinal disc herniation is an injury to the cushioning and connective tissue between vertebrae, usually caused by excessive strain or trauma to the spine. It may result in back pain, pain or sensation in different parts of the body, and physical ...

and

lumbar In tetrapod anatomy, lumbar is an adjective that means ''of or pertaining to the abdominal segment of the torso, between the diaphragm and the sacrum.'' The lumbar region is sometimes referred to as the lower spine, or as an area of the back i ...

fracture on OOP passengers.

Airbags An airbag is a vehicle occupant-restraint system using a bag designed to inflate extremely quickly, then quickly deflate during a collision. It consists of the airbag cushion, a flexible fabric bag, an inflation module, and an impact sensor. T ...

can prove fatal on OOP passengers: modulating the airbag folding pattern has been proposed as a method to reduce injuries. Crash testing has shown increased forces acting on the

neck The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...

and

torso The torso or trunk is an anatomical term for the central part, or the core, of the body of many animals (including humans), from which the head, neck, limbs, tail and other appendages extend. The tetrapod torso — including that of a human � ...

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.

References

{{transport-stub

External Weblinks

U.S. FMVSS 208 Test Configurations
Transport safety