Effect of Head and Body Position and Muscular Tensing on Response to Impact

Human volunteers were exposed to increasing levels of sled acceleration and velocity during simulated barrier crashes while seated in a padded, bucket automobile seat and restrained by an advanced, passive, three-point belt which contained energy-absorbing fibers and was integral with the seat structure. By muscular tensing, bracing, and riding with the head flexed, two of the subjects were exposed to crash velocities as high as 30.0 mph (over 33 mph, total velocity change), without suffering significant pain or injury.