1. Injury & Osteoporosis Research Center, UKK Institute for Health Promotion Research, Tampere, Finland;
2. Medical School, University of Tampere, Tampere, Finland;
3. Department of Orthopedics and Trauma Surgery, Tampere University Hospital, Tampere, Finland;
4. Tampere Research Center of Sports Medicine, UKK Institute for Health Promotion Research, Tampere, Finland