Concussion from solid plastic water bottle?
 

Is it possible for a full 1 to 2 lb water landing on the top of my forehead? Because my hard water bottle fell from about 1/2 feet from my locker and landed on my forehead. It caused a small egg on my head, and I also had a concussion a year prior, so would this be enough force to cause a concussion? My water bottle is like a jogging reusable bottle, and is not a throw away.