Weight Perception and Controlling Experience in Loaded Virtual Rehabilitation: Effect of Biased Weight Feedback and Modulated Movement

Virtual reality (VR) exercise-based programs, such as virtual rehabilitation, may require users to perform movements while wearing a rehabilitation device or exoskeleton for effective training outcomes. However, these external weights posed on users are burdensome and may result in fatigue, generating undesired user experiences. We investigated the effect of biased weight feedback with movement augmentation on the weight perception, the feeling of control, and perceived exertion of a VR exercise task for the lower limb. The experiment involved twelve participants and showed that it is possible to deceive the real weight of a weight attached to a person's foot by manipulating the appearance and the movement performed. The reduced weight feedback with movement augmentation to be controlled produced the lightest weight perception of the whole task. The feeling of control can be lower in augmented movement conditions but can be slightly higher when enhanced weight feedback is used. The study result shows promise to be applied in virtual exergames such as virtual rehabilitation that is integrated with physical rehabilitation devices.