Academics have pinpointed rugby tackles which they believe minimise the risk of head injuries.
Analysis by researchers from Trinity College in Dublin showed that tackling the lower trunk of the ball carrier's body - not the upper trunk or upper legs - was safer.
Concussion can be a serious danger to players. Blows to the head have been a factor in deaths and periods out of action.
Associate professor Ciaran Simms said: "The physical and high-impact nature of rugby union has made head injuries and long-term brain health a concern, and the 2016-17 English Premiership rugby union season was the sixth consecutive one in which concussion was the most commonly reported match injury - contributing to 22% of all match injuries during that season.
"Our findings have helped us better understand the mechanisms of head impacts in rugby union and resulted in these recommendations, which we hope may guide prevention strategies and reduce head injury assessment risks for athletes."
In 2014 Ireland international outhalf Johnny Sexton suffered four concussions and was told to serve a 12-week stand-down period.
In March of that year he lay on the pitch at the Stade de France following a collision with Frenchman Mathieu Bastareaud.
PhD researcher Gregory Tierney, from Trinity College Dublin's School of Engineering and Centre for Bioengineering, said head injury prevention strategies should place emphasis on tackling lower-risk body regions such as the lower trunk.
Nearly four out of five (77%) tackler head injuries requiring assessment were caused by tackles to the upper trunk (47%) and upper legs (30%).
He said: "The findings from this project provide an evidence base, at the elite level, for coaches to develop and implement technical-based concussion prevention strategies for players."
He added: "Tackling at the upper trunk of the ball carrier should be discouraged.
"Instead, coaching strategies should place emphasis on tackling at lower head injury assessment risk body regions such as the lower trunk.
"Furthermore, there needs to be a greater focus placed on safe contact technique in the tackle.
"We identified easy-to-coach characteristics, such as keeping your head up, eyes on the ball carrier and feet active, that can really help reduce head injury assessment risk.
"Surprisingly, these characteristics are not always exhibited by elite players."