A series of human volunteer experiments has been conducted to measure the inertial response of the head and the first thoracic vertebra (T1) to +Gy whole body impact acceleration;​ that is, acceleration applied to the subject from right to left. The 12-inch HYGE® accelerator, instrumentation system and procedures were identical to those used for measuring the response to -Gx impact acceleration, previously reported.

Three categories of sled acceleration profile were used:​ high onset, long duration from 2G to 7.5G with end stroke sled velocity limit of 6.5 meters/sec;​ low onset, long duration with the same peak acceleration and velocity limits;​ and high onset, short duration from 5G to 11G. Comparison time profiles of angular acceleration, angular velocity and linear resultant acceleration at the head anatomical origin and horizontal linear acceleration at the T1 origin are presented at selected peak sled acceleration levels for 5 subjects of various anthropometric dimensions.