title: Hard knocks.
authors.forename: I K
authors.initials: IK
authors.lastname: Smith
mesh_terms: D000293:Adolescent; D001265:Athletic Injuries; D001924:Brain Concussion / Q000145:classification* / Q000175:diagnosis; D002648:Child; D006801:Humans; D010290:Parents; D017410:Practice Guidelines as Topic; D015599:Trauma Severity Indices; D014481:United States