Hans-Rudolf Weiss1
, Shay Bess2
, Man Sang Wong3
, Vikas Patel4
, Deborah Goodall5
and Evalina Burger4 
1Asklepios Katharina Schroth Spinal Deformities Rehabilitation Center, D-55566 Bad Sobernheim, Germany
2Colorado Spine and Scoliosis Institute, Lonetree, CO, 80124, USA
3Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong, PR China
4Departmet of Orthopedics, University of Colorado School of Medicine, Denver, CO, USA
5Rehabilitation services, Ealing Hospital, Uxbridge Road, Southall, London, UB1 3HW, UK