When a child is in a forward-facing seat, there is tremendous stress put on the child's neck, which must hold the large head back. The mass of the head of a small child is about 25% of the body mass whereas the mass of the adult head is only 6%! A small child's neck sustains massive amounts of force in a crash. The body is held back by the straps while the head is thrown forward - stressing, stretching or even breaking the spinal cord. The child's head is at greater risk in a forward-facing seat as well. In a crash, the head is thrown outside the confines of the seat and can make dangerous contact with other occupants, vehicle structures, and even intruding objects, like trees or other vehicles.