Children have round and underdeveloped hip bones, also
called iliac crest, which means seat belt will slide up on abdomen in a collision unless a booster is used.
Vessels commonly blocked include arteries in the lungs, which cause rapid breathing or panting, rapid heart rate and high body temperature, and the
iliac arteries (which supply the back legs), which causes a blockage
called a saddle thrombus, with sudden paralysis of the rear limbs.