1. School of Health and Welfare, Halmstad University, Halmstad, Sweden
2. Faculty of Sport, Applied Health and Performance Science, St Mary´s University, Twickenham, London, UK
3. FIFA Medical, Federation Internationale de Football Association, Zurich, Switzerland
4. School of Applied Sciences, Edinburgh Napier University, Edinburgh, UK
5. Department of Sport Science and Physical Education, University of Agder, Kristiansand, Norway