Received: 24 June 2020
Accepted: 25 January 2021
First Online: 15 February 2021
Ethics Approval and Consent to Participate
: All research procedures were in accordance with the ethical standards of World Rugby, University of Sheffield, and the 1964 Helsinki Declaration and its later amendments. Ethical approval was provided for analysis of the data from the University of Sheffield. All players provided informed consent for use of data prior to the start of the season.
: Not applicable
: Ross Tucker, Eanna Falvey, Marc Douglas, and Martin Raftery are employed by World Rugby. Jon Miles and Prabhat Mathema are employed by Wales Rugby Union. Gordon Fuller has received travel expenses to attend scientific conferences from World Rugby and was a member of the expert panel developing the SCAT5 concussion assessment tool. The authors, Gordon Ward Fuller, John Miles, Ross Tucker, Marc Douglas, Martin Raftery, Eanna Falvey and Prabhat Mathema declare that they have no other conflicts of interest.