title: Movement visualisation in virtual reality rehabilitation of the lower limb: a systematic review.
abstract: BACKGROUND
  Virtual reality (VR) based applications play an increasing role in motor rehabilitation. They provide an interactive and individualized environment in addition to increased motivation during motor tasks as well as facilitating motor learning through multimodal sensory information. Several previous studies have shown positive effect of VR-based treatments for lower extremity motor rehabilitation in neurological conditions, but the characteristics of these VR applications have not been systematically investigated. The visual information on the user's movement in the virtual environment, also called movement visualisation (MV), is a key element of VR-based rehabilitation interventions. The present review proposes categorization of Movement Visualisations of VR-based rehabilitation therapy for neurological conditions and also summarises current research in lower limb application.
  
  
  METHODS
  A systematic search of literature on VR-based intervention for gait and balance rehabilitation in neurological conditions was performed in the databases namely; MEDLINE (Ovid), AMED, EMBASE, CINAHL, and PsycInfo. Studies using non-virtual environments or applications to improve cognitive function, activities of daily living, or psychotherapy were excluded. The VR interventions of the included studies were analysed on their MV.
  
  
  RESULTS
  In total 43 publications were selected based on the inclusion criteria. Seven distinct MV groups could be differentiated: indirect MV (N = 13), abstract MV (N = 11), augmented reality MV (N = 9), avatar MV (N = 5), tracking MV (N = 4), combined MV (N = 1), and no MV (N = 2). In two included articles the visualisation conditions included different MV groups within the same study. Additionally, differences in motor performance could not be analysed because of the differences in the study design. Three studies investigated different visualisations within the same MV group and hence limited information can be extracted from one study.
  
  
  CONCLUSIONS
  The review demonstrates that individuals' movements during VR-based motor training can be displayed in different ways. Future studies are necessary to fundamentally explore the nature of this VR information and its effect on motor outcome.
authors.affiliation: Rehabilitation Robotics Group (TU Berlin/ Fraunhofer IPK), Department of Industrial Automation Technology, Technische Universität Berlin, Pascalstr. 8-9, 10587, Berlin, Germany. luara.santos@iwf.tu-berlin.de.|DFG Research Training Group Prometei, Technische Universität Berlin, Marchstr. 23, 10587, Berlin, Germany. luara.santos@iwf.tu-berlin.de.
authors.forename: Luara
authors.initials: L
authors.lastname: Ferreira Dos Santos
authors.affiliation: Institute Humans in Complex Systems, School of Applied Psychology, University of Applied Sciences and Arts Nortwestern Switzerland, Riggenbachstrasse 16, Olten, Switzerland.
authors.forename: Oliver
authors.initials: O
authors.lastname: Christ
authors.affiliation: School of Physical and Occupational Therapy, McGill University, 3654 Promenade Sir William Osler Montreal, Quebec, H3G 1Y5, Canada.
authors.forename: Kedar
authors.initials: K
authors.lastname: Mate
authors.affiliation: Rehabilitation Robotics Group (Fraunhofer IPK/ TU Berlin), Department of Automation Technology, Fraunhofer Institute for Production Systems and Design Technology (IPK), Pascalstr. 8-9, 10587, Berlin, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Schmidt
authors.affiliation: Rehabilitation Robotics Group (TU Berlin/ Fraunhofer IPK), Department of Industrial Automation Technology, Technische Universität Berlin, Pascalstr. 8-9, 10587, Berlin, Germany.|Rehabilitation Robotics Group (Fraunhofer IPK/ TU Berlin), Department of Automation Technology, Fraunhofer Institute for Production Systems and Design Technology (IPK), Pascalstr. 8-9, 10587, Berlin, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Krüger
authors.affiliation: Department of Neurological Rehabilitation, MEDIAN Klinik Berlin-Kladow, Kladower Damm 223, 14089, Berlin, Germany.|Center for Stroke Research Berlin, Charité-University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Dohle
mesh_terms: D000203:Activities of Daily Living; D003198:Computer Simulation; D005684:Gait; D006801:Humans; D035002:Lower Extremity / Q000503:physiopathology*; D009048:Motor Skills; D009068:Movement; D009422:Nervous System Diseases / Q000534:rehabilitation*; D004856:Postural Balance; D020127:Recovery of Function; D000071939:Stroke Rehabilitation / Q000379:methods*; D014584:User-Computer Interface; D018910:Video Games