Abstract
This paper describes an investigation of a potential methodology for studying the relationship between real world crash characteristics, crash forces and neck injury. Mechanisms involved in producing neck strain or whiplash like injuries are generally poorly defined. This is largely due to problems associated with identifying the extent to which any one single mechanism is responsible for all or some of the injury reported. One of the major dilemmas with the study of neck injury mechanisms thus far has been the inability to correlate mechanisms identified in the laboratory with what occurs in the real world. An example of this is the role cervical facet joint motion may have as a source of pain in neck strain or whiplash like injury. Yoganandan et al [1] have studied the motion of these joints in great detail in laboratory settings and believe that compression of the facets during the initial loading phase may explain the occurrence of a significant proportion of reported minor neck injury. In addition, clinical work reported by Lord et al [2] have shown that the facet capsules are a likely source of pain in sufferers of long term chronic pain. However establishing the motions of the individual cervical segments in real world situations, and the vehicle/crash factors that influence this motion is difficult. This is largely due to the problem of studying the nature of the loads produced in the cervical region in occupants in the variety of impact situations that might occur in the real world.
An experimental methodology has been developed to try and overcome some of these difficulties by investigating crashes and then matching them to laboratory crashes, where accelerations have been measured. This acceleration is then used as an input to a mathematical model of the human neck. This methodology has been trialed on a subset of crashes investigated and matched to laboratory test in frontal, side and rear impacts at varying degrees of severity. Observations made from the predictions of the human model in these trials are also reported.
The use of this method in terms of estimating real world crash pulses for use in mathematical models has been found to be a robust approach. However, further refinement and validation of the available models is required, and a wider range of available crash test impacts types is needed before this method can be extended to large samples of real world crashes.