Read this expert from heads-up on sporty safety the dangerous to your health depends on the spur of us some general principles God helmet design Krista Hillman needs to be at school and lightweight and comfortable as possible second the helmet needs to be hard enough and fit well enough to protect the school and bread for some athletes Tchaikovsky goalies or baseball catchers the helmet also need to protect the face from fast Punch or boss 3rd and must must not prevent the what the wear from seeing or hearing for that can I be caused from injuries then it prevent it turns out that the way to address many of these concerns is to to use hard but flexible light strong metals materials on the outside and soft materials on inside scientist create the new plastic all the time but sometimes the best design comes from using old materials and new ways and one recent design makes the shelf helmets out of Kevlar, the same kind of white plastic used in bulletproof vest vest which is a key detail that supports the main idea that there are general principles that guide sports helmet design