Human and manikin head/neck response to +Gz acceleration when encumbered by helmets of various weights.

A series of +Gz impact tests were performed on the Armstrong laboratory vertical decelerator with human and manikin subjects wearing various helmet-mounted systems. The resulting data were used to quantify the effects on human dynamic response of varying helmet mass and seat acceleration as well as to provide comparisons to previously established safe limits of impact exposures. Tests with human subjects and a 97th percentile manikin were performed at seat impact levels of up to + 10 Gz for human and + 15 Gz for manikins, with standard and prototype helmet-mounted systems weighing from 3.2 to 6.6 lb. The results showed that increases in the helmet weight and seat acceleration resulted in increased compression, shear, and rotational forces on the neck. With helmet weights greater than 4.5 lb during +15 Gz impacts, neck compression force began to exceed established cadaver injury limits.