the main purpose of this research was to compare the rate of body checking injuries between two provinces that introduce body checking at different ages (age 12 versus 14). three teams from ontario (body checking introduced at age 12) and three teams from quebec (body checking introduced at age 14) were used in each of the 10 and 11, 12 and 13, and 14 and 15 year old levels. a total sample of 294 players were involved in the study for one full hockey season, from august of 1993 to april of 1994.