The league announced Saturday the "progressive elimination" of body checking, starting with minor bantam for the 2015-16 season.
The GTHL board of directors proposed the rule change — which was approved by GTHL member clubs and associations with a majority vote of 326 to 195 — as a result of feedback received from a league-wide survey on the topic of body checking conducted during the 2013-14 season.
The majority of respondents in the survey supported the removal of body checking at the "A" level, which is a competitive league under triple-A and double-A.
"There is now a mountain of evidence demonstrating the negative effects of body checking in hockey and it is clear that it can account for 50 per cent or more of all concussions," said Dr. Michael Cusimano, a neurosurgeon at Toronto's St. Michael's Hospital.
"While estimates vary depending on the particular league, with a move like the one the GTHL has made, one could expect a threefold reduction in injuries."
The minor bantam level consists of 12 and 13-year-old players. Founded in 1911, the GTHL is the largest minor hockey league in the world with more than 40,000 annual participants in Toronto, North York, Scarborough, Vaughan and Markham, ranging from age 4 to 20.