1 Department of Sports and Clinical Biomechanics (Roos, Thorlund, Juhl, Lohmander), University of Southern Denmark, Odense; Department of Orthopedics (Juhl), Copenhagen University, Copenhagen; Department of Orhtopedics and Traumatology (Lohmander), Odense University Hospital, Odense, Denmark; Department of Orthopedics (Lohmander) Clinical Sciences Lund, University of Lund, Sweden.