1. Department of Computer Science and Engineering, Universidad Carlos III de Madrid, Spain
2. Computer Science, Universidad Carlos III de Madrid, Spain
3. Uppsala University, Dept of Informatics and Media, Sweden
4. Human Media Interaction, University of Twente, Netherlands
5. Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark
6. University of Southern Denmark, Denmark
7. Department of Computer Science and Engineering, Universidad Carlos III de Madrid, Spain and UCL Interaction Centre, University College London, United Kingdom