Examining computerized software reliability to measure individual exposure time.
OBJECTIVE
Epidemiological sport injury research lacks relevance when all athletes are assumed to have equal time exposed to risk. Because athletes do not play equal minutes in ice hockey games, it is important to control for players' individual exposure times (IETs) when studying risk factors for injury.


METHODS
Cohort study.


METHODS
Hockey games.


METHODS
Twenty-eight Minnesota Junior A hockey players.


METHODS
Individual exposure times were measured on all players dressed for their home games using both a manual (game clock, paper, and pencil) and a computer-based system [Time on Ice (TOI) software]. A sample of matched records was evaluated to compare the 2 methods of recording exposure.


METHODS
Values of individual player exposure times obtained by TOI software designed for hockey and the manual recording method were compared.


RESULTS
Individual exposure times were measured simultaneously by computer-based and manual methods. For 26 games, it would require 156 hours to determine IET per game by the manual method. Conversely, IET totals on TOI software were computed automatically for each player per game. When IET was compared across periods and games, the computer analysis consistently totaled more IET than the manual method.


CONCLUSIONS
Time on Ice software was user friendly, required no postgame processing, and showed a high degree of correlation to manually recorded times, although consistently higher IET per player per period than the manual method was noted.
*Sports Medicine Center, and Departments of †Orthopedic Surgery, ‡Health Sciences Research, and §Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, Minnesota; and ¶Department of Kinesiology, University of Calgary, Calgary, Alberta, Canada.
Aynsley M
AM
Smith
Michael J
MJ
Stuart
Dirk
D
Larson
Daniel
D
Gaz
Casey
C
Twardowski
David
D
Krause
Brian
B
Benson
D015331:Cohort Studies; D006688:Hockey / Q000706:statistics & numerical data*; D012984:Software