Prien, Annika
Grafe, Alexander
Rössler, Roland
Junge, Astrid
Verhagen, Evert
Funding for this research was provided by:
Fédération Internationale de Football Association
Article History
First Online: 18 January 2018
Compliance with Ethical Standards
:
: The authors gratefully acknowledge FIFA (Fédération Internationale de Football Association) for the funding of this review.
: Annika Prien, Alexander Grafe, Roland Rössler, Astrid Junge and Evert Verhagen declare that they have no conflicts of interest relevant to the content of this review.