Biodynamic simulations of helmet mass and center-of-gravity effects

The addition of extraneous devices (such as night vision goggles) to the helmet assembly has created a new safety hazard for the aviator. The additional mass and misplaced center of gravity (cg) associated with these devices poses the threat of neck injury during ejection, windblast, parachute opening, and other high-G maneuvers. Computer biodynamic simulations using the Articulated Total Body model shows that additional mass has very little effect on head injury scales, head/neck torques, and flexion angles. On the other hand, any combination of cg offset or initial head rest position that causes the head/helmet assembly cg to be anterior of the head/neck joint results in significant head rotation, head torques, and head injury scale values.