[Stress and kinematic analysis of the head and neck in frontal collision. A comparison of voluntary probands and postmortem human test cadavers].

Investigations comparing dynamics and kinematics in volunteers and postmortem human subjects (PMHS) under the same collision conditions are rare, although such results are of elementary importance in order to estimate the suitability of PMHS as injury indicators in crash tests. Under this aspect, a report on 12 experimental frontal collisions has been made where PMHS were loaded and restrained by a 80 mm broad double shoulder lap-step belt. The impact velocity amounted 60 km/h, the mean vehicle decelerations were at 11 g and 15 g. In the Naval Biodynamics Laboratory in New Orleans, the comparing collective of 9 volunteers in the age range of 18 to 22 years has been investigated by a mean deceleration of 11 g at otherwise comparable conditions. Optical targets have been fixed at the 1st thoracic vertebra, the occiput and the top of the head in the PMHS, the collision phase has been documented by a laterally to the sled mounted high-speed camera with a frame rate of 1000 p/s. The accelerations have been measured tri-axial at the top of the head, at the clivus and the 1st thoracic vertebra. For the simulation of the muscle tonus of the volunteers, formaldehyde has been injected into the neck muscles. In the PMHS as well as in the volunteers no thoracic- or abdominal injuries occurred during the above mentioned loads. However, the spinal column of the PMHS remained uninjured only in 3 cases, in 7 cases hemorrhages in the intervertebral disc, lacerations of the ligamentum flavum or hemorrhages in the vertebral joints were observed.