Head-neck injuries occur frequently in pedestrian and occupant
automotive accidents even at relatively low speeds. This paper
describes the results of laboratory impact experiments using human
cadavers in pedestrian/vehicle impacts and lateral-to-medial head
impacts at well-known, controlled speeds. Cerebral trauma, with and
without skull fracture, is discussed as a function of impact
configuration and velocity. Cervical spine and cord injuries are
also discussed with regard to the same parameters. Data presented
include impactor mass and velocity, head acceleration measurements,
complete autopsy and dissection results, and the clinical
evaluation of the effect on a person of the observed trauma.
Eighteen cadavers have been exposed to lateral-to-medial head
impacts by two mechanisms. Eight of the subjects were exposed to
pedestrian impacts wherein their head contacted the hood of the
striking vehicle, and 10 were subjected to linear impactor tests in
which the head was struck by a 52 lb impactor with a flat faceplate
that was rigid for some experiments and padded for others. The
presentation and discussions of these experiments in this paper
will be directed toward the clinical results and evaluations of the
trauma observed in the brains of the cadavers in addition to the
measurements of accelerations and the calculations of the Head
Injury Criterion (HIC) values. It must be understood at the outset
that while lesions in areas of the brain can be determined in
impact experiments using human cadavers, and the bodily functions
that would be affected by the lesions in these various areas can be
identified, the extant functions over a period of time cannot be
determined. Even with sectioning of the brain and quantification of
the depth (for example) of the trauma in a given area, it is not
possible to ascertain the level of recovery that a living subject
might be capable of achieving. It is the belief of the authors,
however, that the reporting of the types of trauma to the brain and
the functional impairment that may be realized (even qualitatively)
from specified impacts is important as initial data base
information for dissemination to the transportation safety
community.
Cadaver selection criteria and the handling and testing
protocols were the same for these experiments as those
described.