- 50% of "second impact syndrome" incidents – brain injury caused from a premature return to activity after suffering initial injury (concussion – result in death.
- Emergency department visits for concussion sustained during organized team sports doubled among 8-13 year olds between 1997 and 2007 and nearly tripled among older youth.
- 8% of football players who sustain a concussion severe enough to cause loss of consciousness return to play the same day.
- As many as 80% of concussions go unrecognized, and traumatic brain injuries among high school athletes is a "silent epidemic."
- A field study by the Congress of Neurological Surgeons measured head impacts among collegiate football players to gauge the relationships between the impact's location and magnitude with the severity of symptoms experienced by the athlete. Because there was not a statistically significant relationship, it may be difficult to establish a standard threshold for concussive injury.