1 Department of Neurology, University of California, 200 S. Manchester Ave., Suite 206, Irvine, CA, 92868, USA; Department of Epidemiology, School of Public Health, University of California, 650 Charles Young Drive, South Box 951772, Los Angeles, CA, 90095, USA; World Spine Care, 801 North Tustin Avenue, Suite 202, Santa Ana, 92705, CA, USA.
2 World Spine Care, 801 North Tustin Avenue, Suite 202, Santa Ana, 92705, CA, USA; Department of Orthopedic Surgery, Occupational and Industrial Orthopedic Center (OIOC), New York University, 63 Downing Street, New York, NY 10014, USA. Electronic address: Margareta.nordin@nyu.edu.
3 World Spine Care, 801 North Tustin Avenue, Suite 202, Santa Ana, 92705, CA, USA.
4 Office of Public Health Studies, University of Hawaii at Manoa, 1960 East-West Road, Biomedical Sciences D201, Honolulu, HI, 96822, USA.
5 Department of Sports Science and Clinical Biomechanics, Faculty of Health Sciences, University of Southern Denmark, Campusvej 55, 5230, Odense M, Denmark.
6 Chiropractic Program, Department of Family and Community Medicine, St. Michael's Hospital, 80 Bond Health Centre, Level 1 Room 12, Toronto, Ontario, Canada, M5B 1X2; Graduate Education and Research, Canadian Memorial Chiropractic College, 6100 Leslie Street, Toronto, Ontario, Canada, M2H 3J1.
7 World Spine Care, Mahalapye District Hospital, P.O. Box 49, Mahalapye, Botswana.
8 Ankara Spine Center, İran Caddesi 45/2 Kavaklıdere 06700, Ankara, Turkey.