Footnotes

• Contributors Lynn Snyder-Mackler advised this dissertation, alongside the dissertation committee of Karin Gravere-Silbernagel, Daniel White, and Stefano Della Villa. Holly Silvers-Granelli, Ryan Zarzycki, Adam Marmon and Celeste Dix all helped with the FIFA11+ study in aspects of data collection, processing, analysis and manuscript editing. Ryan Zarzycki, Jacob Capin and Angela Smith all helped with the ACL-SPORTS study in aspects of data collection, processing and manuscript editing.

• Funding National Institute of Child Health and Human Development (grant number R44 HD068054) and National Institute of Arthritis and Musculoskeletal and Skin Diseases (grant number R01 AR048212). Support was also provided by a Legacy Grant from the Sports Section of the American Physical Therapy Association and a Promotion of Doctoral Studies I Scholarship from the Foundation for Physical Therapy.

• Competing interests None declared.

• Ethics approval University of Delaware Internal Review Board.

• Provenance and peer review Not commissioned; internally peer reviewed.