title: Mechanisms of head injuries in elite football.
abstract: OBJECTIVE
  The aim of this study was to describe, using video analysis, the mechanisms of head injuries and of incidents with a high risk of head injury in elite football.
  
  
  METHODS
  Videotapes and injury information were collected prospectively for 313 of the 409 matches played in the Norwegian (2000 season) and Icelandic (1999 and 2000 season) professional leagues. Video recordings of incidents where a player appeared to be hit in the head and the match was consequently interrupted by the referee were analysed and cross referenced with reports of acute time loss injuries from the team medical staff.
  
  
  RESULTS
  The video analysis revealed 192 incidents (18.8 per 1000 player hours). Of the 297 acute injuries reported, 17 (6%) were head injuries, which corresponds to an incidence of 1.7 per 1000 player hours (concussion incidence 0.5 per 1000 player hours). The most common playing action was a heading duel with 112 cases (58%). The body part that hit the injured player's head was the elbow/arm/hand in 79 cases (41%), the head in 62 cases (32%), and the foot in 25 cases (13%). In 67 of the elbow/arm/hand impacts, the upper arm of the player causing the incident was at or above shoulder level, and the arm use was considered to be active in 61 incidents (77%) and intentional in 16 incidents (20%).
  
  
  CONCLUSIONS
  This study suggests that video analysis provides detailed information about the mechanisms for head injuries in football. The most frequent injury mechanism was elbow to head contact, followed by head to head contact in heading duels. In the majority of the elbow to head incidents, the elbow was used actively at or above shoulder level, and stricter rule enforcement or even changes in the laws of the game concerning elbow use should perhaps be considered, in order to reduce the risk of head injury.
authors.affiliation: Oslo Sports Trauma Research Center, Norwegian University of Sport and Physical Education, P O Box 4014, Ulleval Stadion, 0806 Oslo, Norway. thor.einar.andersen@nih.no
authors.forename: T E
authors.initials: TE
authors.lastname: Andersen
authors.forename: A
authors.initials: A
authors.lastname: Arnason
authors.forename: L
authors.initials: L
authors.lastname: Engebretsen
authors.forename: R
authors.initials: R
authors.lastname: Bahr
mesh_terms: D001132:Arm; D006259:Craniocerebral Trauma / Q000209:etiology*; D005528:Foot; D006257:Head; D006801:Humans; D007055:Iceland; D008297:Male; D009664:Norway; D011446:Prospective Studies; D012307:Risk Factors; D012916:Soccer / Q000293:injuries*; D014743:Videotape Recording