In past years, Aspetar has supported clinically orientated research. This has led to greater practitioner involvement in both projects design and interpreting whether outcomes are clinically meaningful. Now we have also improved the communication of our findings to our stakeholders (players, sporting authorities, community leaders and governing bodies). This growing awareness is no more apparent than in the wealth of work around hamstring injuries, particularly in football.

Aspetar currently hosts the largest clinical data set worldwide on acute hamstrings injuries and has established a strong research infrastructure.

Over the years we have learned that the value for MRI in predicting return to play is limited and inferior to standardized clinical assessment, that platelet rich plasma is not the supposed magic bullet to speed up recovery and that Aspetar’s criteria rehabilitation based program enables safe return to play.

To move in the field forward and to answer new emerging questions in the field we need higher numbers and worldwide collaboration between the di erent research centres.

This targeting issue on Hamstring Injuries in football is our latest update on years of common e orts of the team in Aspetar, Aspire Academy and the National Sports Medicine Program (NSMP) on this topic.

I would like to thank our guest editor Nicol Van Dyk for his outstanding work to make this issue possible and to all the authors for their valuable contribution making their sport a safer environment for our athletes.

Nebojsa Popovic MD PhD

Editor-in-Chief