How reaching kinematics differ between a low-cost 2D virtual environment and the real world

Abstract

Virtual reality interventions are increasingly used in rehabilitation to target sensorimotor impairments in various populations. To verify that the movements practiced in virtual reality applications are similar to the movements to be retrained when performing everyday activities, it is important to understand if movements performed in a virtual and a physical environment (real-life) are similar. The aim of this study is to estimate the extent to which unilateral reach to grasp movements performed in a 2D low-cost virtual environment are kinematically similar to movements performed in a comparable physical environment in healthy individuals. Using a cross-sectional design, 12 right-handed, healthy participants performed reaching to grasp movements with the dominant arm in a low cost 2D virtual and a comparable physical environment. Each movement was repeated 20 times in each environment. Arm and trunk kinematics were recorded using the Optotrak motion analysis system (13 markers; 120 Hz) and 3D kinematics were reconstructed. Temporal and spatial characteristics of the endpoint trajectory and arm and trunk movement patterns were compared between environments using ANOVAs. In the virtual environment, movements were slower, more segmented and the endpoint trajectory was straighter. Ranges of motion of arm and trunk movements did not differ between environments. When using 2D virtual environments for upper limb rehabilitation, differences in movement performance between virtual and physical environments should be taken into account.