Energy-absorbing car seat designs for reducing whiplash.
OBJECTIVE
This study presents an investigation of anti-whiplash features that can be implemented in a car seat to reduce whiplash injuries in the case of a rear impact. The main emphasis is on achieving a seat design with good energy absorption properties.


METHODS
A biofidelic 50th percentile male multi-body human model for rear impact is developed to evaluate the performance of car seat design concepts. The model is validated using the responses of 7 volunteers from the Japanese Automobile Research Institute (JARI) sled tests, which were performed at an impact speed of 8 kph with a rigid seat and without head restraint and seatbelt. A generic multi-body car seat model is also developed to implement various seatback and recliner properties, anti-whiplash devices, and head restraints. Using the same driving posture and the rigid seat in the JARI sled tests as the basic configuration, several anti-whiplash seats are designed to allow different types of motion for the seatback and seat-pan.


RESULTS
The anti-whiplash car seat design concepts limit neck internal motion successfully until the head-to-head restraint contact occurs and they exhibit low NIC(max) values (7 m(2)/s(2) on average). They are also effective in reducing neck compression forces and T1 forward accelerations. In principle, these car seat design concepts employ controlled recliner rotation and seat-pan displacement to limit the formation of S-shape. This is accomplished by using anti-whiplash devices that absorb the crash energy in such a way that an optimum protection is provided at different severities.


CONCLUSIONS
The results indicate that the energy absorbing car seat design concepts all demonstrate good whiplash-reducing performances at the IIWPG standard pulse. Especially in higher severity rear impacts, two of the car seat design concepts reduce the ramping of the occupant considerably.
Himmetoglu
S
S
Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Leicestershire, UK.
Acar
M
M
Bouazza-Marouf
K
K
Taylor
A J
AJ
D000063:Accidents, Traffic; D000328:Adult; D001336:Automobiles; D001696:Biomechanical Phenomena; D049628:Body Size; D004735:Energy Transfer; D004867:Equipment Design; D006260:Head Protective Devices; D006801:Humans; D008297:Male; D008954:Models, Biological; D011187:Posture; D014911:Whiplash Injuries / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*