Parametric analysis of vehicle design influence on the four phases of whiplash motion.
OBJECTIVE
The objective is to establish a basis for motor vehicle test requirements that measure component contributions to Whiplash Associated Disorders (WAD).


METHODS
Selected vehicle design features are evaluated with regard to their relative contributions to WAD measures. The motion of the occupant cervical spine associated with WAD is divided into four phases: retraction, extension, rebound, and protraction. Injury measures from the literature (NIC, extension moment, N(km), and flexion moment) represent the injury potential during each of these phases. Four vehicle design factors that affect WAD motion (vehicle stiffness, seat stiffness, head restraint height and head restraint backset) were evaluated for their contributions to the injury measures. A detailed 50th percentile male model with a biofidelic neck was used in a 100-run Monte Carlo analysis of a rear impact, varying the design factors across the values documented in the literature. Total energy was held constant and Delta V was 10 kph.


RESULTS
Vehicle stiffness has a strong influence on the retraction (70%), rebound (43%), and protraction (47%) phases. Headrest backset demonstrates a strong influence on the extension (49%) and rebound (39%) phases.


CONCLUSIONS
For WAD protection rating, the vehicle should be viewed as a system whereby the complex interactions among the vehicle, seat, and occupant characteristics all contribute to the WAD potential.
Sendur
Polat
P
Crashport, Huntsville, Alabama 35816, USA.
Thibodeau
Robert
R
Burge
John
J
Tencer
Allan
A
D000063:Accidents, Traffic; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae / Q000293:injuries*; D004867:Equipment Design; D019416:Head Movements / Q000502:physiology; D006260:Head Protective Devices; D006801:Humans; D008297:Male; D008348:Manikins; D018986:Motor Vehicles; D014911:Whiplash Injuries / Q000503:physiopathology* / Q000517:prevention & control*