M.B.
I would recommend buying a skate board helmet rather than a standard bicycle helmet. Last summer my 4 yr old son was riding his bike and had a pretty bad wreck. He was wearing a bicycle helmet which we thought would protect him. However, the type of helmet he was wearing did not cover the sides of his head, and he hit the side of his head right above the ear which was not covered by the helmet. After a trip to the emergency room, the doctor recommended that we get a skate board helmet because it does cover the sides of the head. Luckily my son was ok, but I went right out and bought all 3 of my children skate board helmets instead of the standard bicycle helmets.