title: Collision frequency in elite hockey on North American versus international size rinks.
abstract: OBJECTIVE
  Body impact or collision is the risk factor underlying all sports-related concussions. This study sought to determine whether collision rates in elite hockey differ between games played on North American size rinks as compared to games played on larger international size ice surfaces.
  
  
  METHODS
  Videotapes of games from the 2001 and 2002 National Hockey League Stanley Cup finals, World Junior championships and the 2002 Winter Olympics were analyzed, with all collisions counted and separated into various categories (player/player bodycheck, player/player into boards, player/boards, player/ice, head/stick, head/puck). Further subdivisions included collisions involving the head directly or indirectly. Twenty-two games were analyzed, 11 played on the small ice and 11 on the big ice.
  
  
  RESULTS
  Significantly more collisions of all types (in all categories and subdivisions within categories) were found to occur on the smaller North American ice surface (P value differences from 0.01 to 0.00001).
  
  
  CONCLUSIONS
  The results of this study showed significantly fewer collisions of all types in elite hockey games played on the international size ice surface. The comparison groups studied here did differ in some aspects other than ice size and so replication of the findings with even more closely matched groups will be needed before definitive conclusions can be drawn. However, if these findings are replicable, it would suggest that a change to uniform usage of the larger international rinks, with no rule changes or other alterations in the game, could provide direct primary prevention to reduce the number of collisions, and, by extension, concussions, that occur in the sport.
authors.affiliation: Division of Neurology and Krembil Neuroscience Centre, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Wennberg
mesh_terms: D001265:Athletic Injuries / Q000453:epidemiology* / Q000209:etiology; D006688:Hockey / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D009656:North America; D012307:Risk Factors; D014743:Videotape Recording