From this video you can clearly see the intrinsic danger of being a football player. With the amount of contact that is built into the game, it is important to have enough padding to keep the players safe. What has become a better known concern in recent years is the helmet of the football player. After all, the brain is the command center for the body, and the helmet is the hardest piece of equipment on the body. However, the helmet cannot be all hard, because then it would be uncomfortable on the head and it could possibly hurt the player. Thus, different materials compose different parts of the helmet. The outside is made up of polycarbonate plastic (or ABS for younger players that need lighter helmets) and what this does is allows for repeated blows to the helmet without any damage, but just the polycarbonate does not really keep the head safe. It seems like it is more for keeping the helmet from falling apart and from being destroyed. On a molecular level, the amount of force this compound can absorb comes from cyclohexylene rings that basically spread out the force better. What keeps the player safe instead his helmet is the foam. This is what lines the helmet and its function is to spread out the force on a macroscopic level and it is also more of a cushion than the polycarbonate. The best material for this foam is thermoplastic urethane which is basically just the kind of foam that lasts the longest. It is similar to the polycarbonate in that it has very good impact resistance, but again this is a foam so it is designed with the comfort of the wearer in mind instead of just the product not breaking.