Living Human Dynamic Response to —G _x Impact Acceleration II—Accelerations Measured on the Head and Neck 690817

A methodical investigation and measurement of human dynamic response to impact acceleration is being conducted as a Joint Army-Navy-Wayne State University investigation. Details of the experimental design were presented at the Twelfth Stapp Car Crash Conference in October 1968.

Linear accelerations are being measured on the top of the head, at the mouth, and at the base of the neck. Angular velocity is also being measured at the base of the neck and at the mouth. A redundant photographic system is being used for validation. All data are collected in computer compatible format and data processing is by digital computer. Selected data in a stage of interim analysis on 18 representative human runs of the 236 human runs completed to date are presented.

Review of the data indicates that peak accelerations measured at the mouth are higher than previous estimates. The time relationship of the peak resultant mouth accelerations to the peak sled acceleration for this particular accelerator and restraint system is described. The maximum peak resultant mouth acceleration was 47.8 g and the peak mouth angular velocity on another run exceeded 30 rad/sec, on nominal 10 g, 250 g/sec runs. Clinical evaluation of the subjects before and after the runs disclosed no evidence of unconsciousness or neurological deficit attributable to the acceleration.

Representative plots of the human dynamic response are presented, discussed, and compared. A first-order linear regression analysis for the peak mouth resultant acceleration and the peak mouth angular velocity obtainable from the peak sled acceleration is presented.