Analysis of an injury of the head/neck complex due to +Gz impact acceleration

Eighty-two human impact experiments were conducted on the Armstrong Laboratory vertical deceleration tower to determine the influence of short-duration acceleration applied in the +Gz direction. The exposure was a 10 G impact, with the seat back angle 5 degrees aft and a Dynamic Response Index of 12.5. In the series of tests one subject experienced an end plate mid-thoracic vertebral fracture which appeared to be produced by combined axial (+Gz) and hyper flexion loading. Lack of proper initial position and bracing appear to be the primary contributing factors to the observed response differences and possibly the resultant injury.