'Fine line between aggression and controlled violence' - Andrew Porter on breakdown challenge

He stands six foot tall and weighs in at around 19 stone but Andrew Porter still admits that putting his body on the line at the breakdown is "quite scary".

The week began with the news that Ireland star Mack Hansen would miss the Six Nations after suffering a dislocated shoulder at a ruck while playing for Connacht against Munster.

Earlier in the same game, Jack O'Donoghue was carted off in some discomfort following a clearout at a ruck that resulted in a three-game (reduced from six) suspension for Connacht's Byron Ralston.

In his weekly column, RTÉ Rugby analyst Jonny Holland wrote how his own career ended as a result of a breakdown injury.

The former Munster out-half also recalled how Dan Leavy’s playing days were effectively ended after a side-entry clearout.

Ireland lock Paul O’Connell suffered a similar fate when he was injured at a ruck during a Rugby World Cup match against France in 2015.

Donal Lenihan, the former Ireland captain and manager, said this week that rugby continues to "cannibalise itself", referring to the injuries to Hansen and Jimmy O’Brien, and Munster’s incredible list of unavailable players.

About three years ago, officials began a welcome clampdown on illegality at the ruck, quickly penalising the carrier if the ball was not released immediately. The simple move served to reduce the amount of time a jackler was exposed to a big hit.

They were "hot on it", so the expression goes.

Now the focus is on 'side-entry’ and the risk poor technique carries at the breakdown. Look at any game this weekend and you’ll see multiple examples of the grey areas in which players try to gain an advantage.

World Rugby law 15 says that "an arriving player must be on their feet and join from behind their offside line; a