Effects of weight and center of gravity location of head-supported devices on neck loading.

A comprehensive study of the effect of Head-Supported Devices (HSDs) on neck loading during helicopter accidents is presented. The new Articulated Total Body (ATB) model which treats the neck as a deformable segment was used for crash simulation. Different categories of human and manikin subjects were considered under several crash scenarios. Simulations were theoretically designed to include a wide range of HSDs by changing their weights and center of gravity (CG) locations relative to the head, and studying the effects of these changes. Since HSDs were only theoretically included in the model, detachment of specific detachable devices used in most military applications was not modeled in the study. Hence, two typical detachable devices were modeled and selected simulations were repeated and compared not only to provide a measure of accuracy for the original results but also to see the effect of separation of these devices from the helmet.