Virtual reality environments to enhance upper limb functional recovery in patients with hemiparesis.

Impairments in reaching and grasping have been well-documented in patients with post-stroke hemiparesis. Patients have deficits in spatial and temporal coordination and may use excessive trunk displacement to assist arm transport during performance of upper limb tasks. Studies of therapeutic effectiveness have shown that repetitive task-specific practice may improve motor function outcomes. Movement retraining may be optimized when done in virtual reality (VR) environments. Environments created with VR technology can incorporate elements essential to maximize motor learning, such as repetitive and varied task practice, performance feedback and motivation. Haptic technology can also be incorporated into VR environments to enhance the user's sense of presence and to make motor tasks more ecologically relevant to the participant. As a first step in the validation of the use of VR environments for rehabilitation, it is necessary to demonstrate that movements made in virtual environments are similar to those made in equivalent physical environments. This has been verified in a series of studies comparing pointing and reaching/grasping movements in physical and virtual environments. Because of the attributes of VR, rehabilitation of the upper limb using VR environments may lead to better rehabilitation outcomes than conventional approaches.