WHAT IS “WHIPLASH INJURIES”?
“Whiplash injuries” or Whiplash Associated Disorders (WADs) can be sustained in vehicle crashes, with rear impacts being the most common cause. Victims report a variety of symptoms linked to soft tissue neck injuries. The underlying injury mechanism is not yet fully understood from a biomechanical point of view, although relative motion between the head and upper body, as experienced during a crash, is associated with these injuries.
THE STATE-OF-THE-ART TESTING
A sled test is performed to investigate injury protective performances in a collision by seating a crash test dummy on a seat, mounted to a sled. The sled is then subjected to a crash pulse mimicking a collision. To date, the rear impact crash test dummy, the BioRID, is used to evaluate the protective performances. BioRID represents the anthropometry, i.e., the size, weight and weight distribution and stiffness of an average-sized male. To assess the level of injury protection, the dummy is equipped with different sensors which allow measuring of relevant parameters, such as head and upper torso acceleration and forces and moments between the head and neck. Different criteria deemed relevant to assess the injury risks are determined based on the above entries and followed by analysis of the kinematics of the crash test dummy. A static assessment is performed in addition to the dynamic sled tests to establish the initial head-to-head restraint distance. Please note that current seat assessments are primarily performed by consumer organisations such asEuro-NCAP.
WHY ARE NOT ALL OCCUPANTS EQUALLY WELL PROTECTED ?
The protective performance of seat for females is not considered in current test procedures, due to the lack of a crash test dummies representing females. This lack presents a major disadvantage to the safety since it has been established that females are subject to a higher injury risk than males. Test procedures, at present, are limited to a single occupant size, representing an average sized male, seated in one particular position. A greater variety of test conditions, for females as well as males, would make it possible to develop safer seats for a larger part of the population.