title: Does soccer ball heading cause retinal bleeding?
abstract: OBJECTIVE
  To define forces of youth soccer ball heading (headers) and determine whether heading causes retinal hemorrhage.
  
  
  METHODS
  Regional Children's Hospital, youth soccer camp.
  
  
  METHODS
  Male and female soccer players, 13 to 16 years old, who regularly head soccer balls.
  
  
  METHODS
  Dilated retinal examination, after 2-week header diary, and accelerometer measurement of heading a lofted soccer ball.
  
  
  RESULTS
  Twenty-one youth soccer players, averaging 79 headers in the prior 2 weeks, and 3 players who did not submit header diaries lacked retinal hemorrhage. Thirty control subjects also lacked retinal hemorrhage. Seven subjects heading the ball experienced linear cranial accelerations of 3.7 +/- 1.3g. Rotational accelerations were negligible.
  
  
  CONCLUSIONS
  Headers, not associated with globe impact, are unlikely to cause retinal hemorrhage. Correctly executed headers did not cause significant rotational acceleration of the head, but incorrectly executed headers might.
authors.affiliation: School of Medicine, University of Washington, Seattle, WA, USA.
authors.forename: William F
authors.initials: WF
authors.lastname: Reed
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Feldman
authors.forename: Avery H
authors.initials: AH
authors.lastname: Weiss
authors.forename: Alan F
authors.initials: AF
authors.lastname: Tencer
mesh_terms: D000054:Acceleration / Q000009:adverse effects; D000293:Adolescent; D001265:Athletic Injuries / Q000453:epidemiology / Q000209:etiology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D012166:Retinal Hemorrhage / Q000453:epidemiology / Q000209:etiology*; D012916:Soccer; D014861:Washington / Q000453:epidemiology