World Rugby's clampdown on high and dangerous tackles has resulted in a 12 per cent reduction in concussion-related incidents at the 2019 World Cup compared with the last tournament four years ago, the sport's governing body said on Wednesday.
The average number of injury replacements has dropped from 2.08 per match at the 2015 event to 1.13 in Japan, while concussion rates are down by 35 per cent when compared to elite competition levels last season.
World Rugby added that no delayed concussions have been reported, and the concussion rates at the ongoing tournament are 10.5 concussions per 1,000 player hours, compared with 12.5 in 2015.
"Our commitment to player welfare is unwavering and a core pillar of our strategies is to reduce injuries," World Rugby chairman Bill Beaumont said in a statement .
"It is highly encouraging that Rugby World Cup 2019 has demonstrated extremely positive outcomes in this priority area."
Japan 2019 is the first World Cup to introduce the high tackle framework, which is designed to reduce risk of head injuries by "changing player behaviour from high-risk upright to lower-risk bent at the waist tackles".
"At this tournament, and in the tests since May, we have been looking to protect players by changing culture and getting the tackler lower," World Rugby chief medical officer Dr Martin Raftery said.
"These very positive outcomes suggest that the teams have embraced the challenge and that risk has lowered at this Rugby World Cup, which is very encouraging."