A helmet is not going to save you from a concussion caused by your brain sloshing in your skull when it suddenly stops moving when it hits the ground. It WILL prevent your skull bones from breaking apart when your head hits the ground, and/or your brains from splattering all over the place like a crushed watermelon if your head comes into contact with something hard and relatively sharp when you fall (curb, rocks, tree-limbs, etc.).