The trial will take place in the 43-match Championship Cup competition, English rugby’s second tier, and represents a major player safety initiative.
Details announced by the RFU change the definition of a high tackle from above the line of the shoulders to above the armpit line. RFU professional rugby director Nigel Melville said: “The Championship Cup provides an opportunity for us to assess the impact of lowering the height of the tackle on the elite adult game, and will be a critical part of helping us develop game-wide approaches to concussion and injury reduction.”
The move has been made in collaboration with World Rugby and will bring about an amendment to law 9.13 operating in the cup competition, which starts on 10 November.
In a statement, the RFU said: “The trial aims to assess the impact of introducing a lower tackle height in elite adult rugby on the incidence of concussion and other injuries, player behaviour in the tackle, the nature of tackles, head injury events and other game events.
“This important player welfare initiative will include all 43 games in the pool stages and play-off rounds of the competition.
“A detailed analysis of this trial will be compared to existing data from the English professional game to help inform any wider approach.
“All data will be shared with World Rugby to be added to research collected from a similar trial in the World Rugby Under-20 Trophy competition.”
The RFU’s latest professional rugby injury surveillance report showed that 47 per cent of all match injuries are associated with the tackle.
Additionally, concussion accounted for 19 per cent of all injuries to the ball-carrier and 43 per cent of all injuries to the tackler.
Melville added: “We believe lowering the height of the tackle will benefit both the ball-carrier and the tackler.”
An initial meeting will take place early next month for rugby directors, coaches and senior player representatives from all Championship clubs, as well as referees and assistant referees, to ensure sufficient preparation time ahead of the competition.
World Rugby chairman Bill Beaumont said: “World Rugby applauds the RFU and the Championship Cup clubs for embracing this important trial.
“The global game is committed to an evidence-based approach to injury prevention.
“The outcomes from this trial, coupled with those from the World Rugby Under-20 Championship and Under-20 Trophy events, will provide World Rugby with comprehensive data and feedback to inform our continued commitment to further reducing concussion risk in rugby.”