We had to go through a 2 hour concussion course this year. You can get a concussion from a body blow. The problem is from the brain moving violently inside the skull. The better rated helmets do a better job of deflecting helmet to helmet hits. Proper tackling techniques also help. The Neuro. leading our course has worked with NFL and other athletes. He said the most important thing is to make sure the player is clear of symptoms before returning to play. The problems really happen when players lie about symptoms being gone so they can get back on the field. He said if symptoms are clear the player can return safely, after clearing running test etc. Takes a high school player 5 days to up to 3 weeks in some cases. He said college and Pro players can be symptom free and can safely return in some cases in 3 days. He said a persons brain at 21 years or older is more mature and repairs and recovers more quickly.