These test dummies are loaded with sensors and put through some intense crash scenarios. Via Mashable Daily on YouTube:
NASA Langley Research Center has recently published a video explaining the ways in which they are using mannequins to test the impact that rough landings and splashdowns can have on human bodies. The dummies are equipped with an array of sensors that collect data which simulates how an actual human body would experience the crash.
The researchers are then using all this information to suggest new aviation policies, suit and helmet adjustments or aircraft improvements to ensure the safety of both commercial flight passengers and astronauts.