Embodied the Healthy Arm: Virtual Reality Rehabilitation for Stroke Patients with Proprioceptive Upper-Limb Deficit.

The article focuses on the use of virtual reality (VR) in the rehabilitation of stroke patients with upper-limb motor deficits, particularly addressing the body illusion paradigm to improve motor abilities. Topics include the neuroscience perspective of post-stroke motor deficits, the application of VR in upper-limb rehabilitation, and the Stroke-VR Project's investigation into the effectiveness of embodying a virtual arm for motor rehabilitation.The main consequence of stroke is upper-limb motor deficits, with partial or complete inability to move the right or left arm, depending on which hemisphere is affected, and limited ability to perform grasping tasks due to lack of motor coordination and control of grip and finger strength.2 As a result, activities of daily living such as eating alone, dressing, and performing personal hygiene are challenging, with constant dependence on a caregiver. From a neuroscience perspective, the deficit in planning, preparing, and executing movements is due to damage to the primary motor cortex, which is responsible for body representation, leading to alteration of proprioceptive and kinesthetic signals and the perception of peripersonal space.3 Thus, a stroke could distort the sense of embodiment in terms of ownership, agency, and location that enables the person to perceive and coordinate the body according to the environment. Considering the role of neural plasticity, a growing number of studies in the field of multisensory integration techniques use the body ownership illusion to modulate the distorted body representation after brain damage.4 This could be possible because the illusion through virtual reality (VR) improves the reorganization of the body representation, demonstrating its effectiveness in upper-limb rehabilitation.