title: Bicycle helmet legislation and injury patterns in trauma patients under age 18.
abstract: BACKGROUND
  The California statewide helmet law was enacted in 1994, and required all cyclists under age 18 y to be helmeted when riding a bicycle. The purpose of this study is to describe helmet use patterns, rates of head and intra-abdominal injury in Los Angeles County before and after helmet legislation, and to determine if increasing helmet use is changing injury patterns.
  
  
  METHODS
  We conducted a retrospective review of trauma patients under age 18 y in the Los Angeles County trauma database between 1992 and 2009 injured while riding bicycles. We examined the variables of age, gender, race, Glasgow Coma Score, Injury Severity Score, presence of head injury, presence of abdominal injury, and use of protective helmet.
  
  
  RESULTS
  During this time period, there were 44,187 injured children less than 18 y of age, and there were 1684 bike-related traumas with data on helmet use. Injury patterns did not change after the helmet law, with head injuries predominating.
  
  
  CONCLUSIONS
  The rate of helmet use did not change after California legislation, and head injury remains a major source of morbidity. Rates of abdominal injury over this time period did not change. Novel strategies are needed to increase helmet use in at-risk populations.
authors.affiliation: Department of Surgery, Children's Hospital Los Angeles, and Keck School of Medicine, University of Southern California, Los Angeles, California 90027, USA.
authors.forename: Shannon L
authors.initials: SL
authors.lastname: Castle
authors.forename: Rita V
authors.initials: RV
authors.lastname: Burke
authors.forename: Helen
authors.initials: H
authors.lastname: Arbogast
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Upperman
mesh_terms: D000293:Adolescent; D001265:Athletic Injuries / Q000453:epidemiology*; D001642:Bicycling / Q000331:legislation & jurisprudence*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006260:Head Protective Devices; D006801:Humans; D007223:Infant; D015141:Los Angeles / Q000453:epidemiology; D008297:Male; D012189:Retrospective Studies