What is the "second impact" during a car wreck?

The "second impact" refers specifically to the scenario where the occupants of a vehicle collide with the interior of the car during a crash. This phenomenon occurs because, during a sudden stop or collision, the body of the occupant continues to move forward at the speed of the vehicle until it encounters the interior surfaces like the steering wheel, dashboard, or windshield. This kind of impact can result in significant injuries, particularly to the head and torso, and is often more severe than the initial impact with the other vehicle or object. Understanding this concept is critical for emphasizing the importance of wearing seat belts and using appropriate safety restraints, as these measures help to reduce the risk of injury from that secondary collision.