Development of Tensed Musculature in the CAVEMAN Human Body Model for Simulating Airmen Injury Risk

The U.S. Air Force has a national defense-related mission need in the area of biodynamic human body modeling of airmen in extreme dynamic loading environments for aircraft ejection, sustained G maneuvers, and helmet mounted mass related injury risk.  Computational models capable of providing expected loads, accelerations, and injury risks under these loading conditions would greatly reduce cost of qualifying technology for the airman, while at the same time shortening the time to flight (airworthiness) through a reduced test schedule.  Current injury biomechanics models have focused on the passive response of relaxed occupants in injury causing events.  However, aircraft ejection events are often triggered by the airman while in a tensed or braced state.  The act of bracing can induce significant preloading within the human skeletal system, increasing the forces propagated through the body during the ejection event and potentially changing the resultant injury risk.  The proposed effort will enhance the existing muscle activation capabilities within the high-fidelity CAVEMAN human body model through incorporation of realistic preloading conditions in each of the muscles within the body, creating the capability to assess injury risk in the tensed airman.