Brain ConcussionAthletic InjuriesPost-Concussion SyndromeHockeyFootballBrain InjuriesSeverity of Illness IndexUnconsciousnessHead Protective DevicesAthletesHead Injuries, ClosedBrain Injury, ChronicMouth ProtectorsTrauma Severity IndicesSports MedicineSports EquipmentBoxingDiffuse Axonal InjuryNeuropsychological TestsBlast InjuriesInjury Severity ScoreCraniocerebral TraumaCognition Disorders