Data extraction
| Reference | Year of publication | Sport | Participants: country of origin | Gender | Subjects: athlete level | Relevant outcome |
| Bjørneboe et al35 | 2010 | Soccer | Norway | Male | First team players from one club in Norwegian Professional League. | Concussion |
| Ekstrand et al36 | 2011 | Soccer | Sweden, Norway, Netherlands, Finland, Ireland, Scotland, Switzerland and Austria | Male and female | Elite first team players from clubs across countries in Europe. | Concussion |
| Fuller et al30 | 2007 | Soccer | USA | Male and female | American college and university teams on NCAA Injury Surveillance System. | Head/neck injury |
| Fuller et al31 | 2010 | Rugby union | UK and Hong Kong | Male | 6 teams from Division One Rugby Hong Kong. 2 teams from English Premiership. | Concussion |
| Kordi et al37 | 2011 | Soccer | Iran | Male | Non-professional soccer players – local league in Iran. | Head/face/neck injury |
| Kristenson et al4 | 2013 | Soccer | Sweden and Norway | Male | Professional soccer players in 12 premier league teams in Norway and Sweden. | Concussion |
| Meyers and Barnhill33 | 2004 | American football | USA | Male | 8 USA high school football teams. | Concussion |
| Meyers et al27 | 2010 | American football | USA | Male | 24 American university teams. | Concussion |
| Meyers et al28 | 2013 | Soccer | USA | Female | 13 USA university teams from Division 1A. | Concussion |
| Meyers et al29 | 2016 | Soccer | USA | Male | 11 USA university Division 1A soccer teams. | Concussion |
| Ranson et al32 | 2018 | Rugby union | UK | Male | 2 UK professional rugby teams. | Head injury |
| Soligard et al38 | 2012 | Soccer | Norway | Male and female | Youth soccer teams ages 13–19 years. | Head injury |