<p>This systematic review aims to explore the utilization of motion capture systems (MCSs) and kinematic metrics for analyzing upper limb kinematics within immersive virtual reality (IVR) systems. Through a comprehensive search strategy across various databases, we systematically reviewed scientific papers that met our inclusion criteria. The findings indicate that visual marker-based MCSs remain the most widely used, despite the increasing availability of integrated tracking in commercial virtual reality devices. Study selection of MCSs was influenced by factors such as anatomical coverage, tracking accuracy, portability, and user comfort, reflecting practical considerations in rehabilitation settings. Kinematic metrics varied substantially across studies, typically falling into domains such as speed (movement time, maximum velocity), smoothness (number of velocity peaks), efficiency (hand path ratio), and joint range of motion. However, inconsistencies in how these metrics were defined and applied limit reproducibility and cross-study comparison. To address these issues, we emphasize the importance of selecting and reporting standardized metrics and recommend that future research adopt clinically grounded kinematic domains aligned with established clinical frameworks to enhance the effectiveness and clinical relevance of IVR-based rehabilitation systems.</p>