It is proposed to study some problems in the dynamic response of the human head and spine subjected to various time-dependent external forces. Investigations include: 1) Develop an increasingly realistic three-dimensional dynamic model of the human spine paying particular attention to the eccentric inertial effects of the thoracic, abdominal and cranial cavities. 2) Obtain the material behavior of the intervertebral joint from combined experimental and systems optimization techniques. The experimental response to the complex loading of an intervertebral joint is optimally matched to the output of a finite-element model simulating the same experiment to obtain coefficients. 3) Model the effect on the brain material due to a glancing blow to the head as the asymmetric response of a material-filled thick spherical shell. 4) Construct a finite-element model to simulate the dynamic response of the entire CNS, i.e., the brain, brainstem, spinal cord, to either a direct impact to the skull and/or a whiplash (hyperextension) acceleration. 5) Obtain the dynamic in vivo material properties of the canine spinal cord from its mechanical wave transmission characteristics. 6) Construct a mechanical model of the head and the head-neck junction to simulate the problems of intracranial pressure, linear and angular acceleration measurements. In the in vivo animal experiments, we shall study the number and skull location of implanted linear accelerometers needed to complete the measured input data. 7) Make use of well-known system optimization techniques to rationally provide design guidelines and/or tolerance limits to the protective equipment manufacturer. A previous optimal design procedure for head protection will be extended to account for space constraints. 8) Develop the interests of graduate students and colleagues in this area of trauma biomechanics.