The legal height of a rugby tackle will be lowered next season during a trial aimed at cutting down on concussion and other injuries, rugby bosses announced on Wednesday.
The trial will take place in the 43-match Championship Cup competition, which is contested by clubs in English rugby's second tier.
The definition of a high tackle will be lowered from above the line of the shoulders to above the armpit line.
The move comes after the Rugby Football Union's (RFU's) surveillance report showed that 47 percent 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 percent of all injuries to the tackler.
"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," the RFU said in a statement.
"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," it added.
RFU professional rugby director Nigel Melville said: "We believe lowering the height of the tackle will benefit both the ball-carrier and the tackler.
"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."