1. Department of Biomechanics, Poznan University of Physical Education, Królowej Jadwigi 27/39, 61-871 Poznań, Poland
2. Institute of Applied Mechanics, Poznan University of Technology, Piotrowo 3, 60-965 Poznań, Poland
3. Adult Spine Orthopaedics Department, Poznan University of Medical Sciences, 28 Czerwca 1956r. 135/147, 61-545 Poznań, Poland
4. Institute of Robotics and Machine Intelligence, Poznan University of Technology, Piotrowo 3, 60-965 Poznań, Poland