1. Department of Orthopaedics; Institute of Clinical Sciences at Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
2. IFK Kliniken Rehab; Gothenburg Sweden
3. Orthocenter IFK-Kliniken; Gothenburg Sweden
4. Sahlgrenska University Hospital; Mölndal Sweden
5. Hallands sjukhus; Kungsbacka Sweden
6. Department of Physical Therapy; University of Delaware; Newark Delaware USA