Battlefield casualties are an unfortunate consequence of military service. Over 50% of all penetrating wounds affect warfighters' limbs, and the most fatal injuries result in exsanguinating hemorrhage (i.e., "bleeding out"). In fact, limb hemorrhage accounts for 10% of all combat deaths in contemporary operations (Champion, Bellamy, Roberts, & Leppaniemi, 2003). However, exsanguination from extremity wounds is often preventable; hence, the Department of Defense continues to emphasize the use of hemostatic procedures.
In the U.S. Army, the Tactical Combat Casualty Care doctrine directs the liberal use of tourniquets (Parsons, 2010), and first responders learn to use the Combat Application Tourniquet® to stop extremity bleeding. Unfortunately, Soldiers typically practice tourniquet application on makeshift training devices, such as a 2×4 wooden plank wrapped with carpet or low-fidelity simulator. Although this helps large numbers of trainees experience tourniquet application, it can have negative training effects. Other training facilities ask trainees to apply tourniquets to one other. This also yields negative training because trainees can only tighten tourniquets to the pain tolerance of their buddies, which may not correspond with the pressure required to stop a real wound.
To address this training gap, the Army has developed the Multiple Amputee Trauma Trainer® (MATT®) simulator, a lifelike lower-limb amputee that includes animatronic movement, bleeding, and physical resistance. Although other tourniquet part-task trainers exist, the MATT® is one of the few that incorporates realistic movement during tourniquet application. To evaluate the training impact of the animatronic movement, we conducted a between-subjects, repeated-measures experiment with 41 Reserve Soldiers. In this paper, we present the results of this study, including the positive correlation between simulator movement and increased trainee speed over time. We also describe the history and contemporary usage of tourniquets, summarize the Army's bleeding intervention procedures, and discuss recommendations for emerging medical simulators.