## 2 State of the Art  
Over the past two decades, research has consistently demonstrated the robust potential of Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR) technologies in medical rehabilitation, particularly within exercise-based interventions. These technologies are rapidly advancing, complementing the limitations of traditional rehabilitation approaches and opening new possibilities by offering real-time feedback, immersive training environments, and enhanced patient motivation. AR/VR rehabilitation is being utilized across diverse clinical scenarios, including phantom limb pain management, post-stroke functional recovery, hand rehabilitation, and geriatric rehabilitation, with a specific focus on improving movement accuracy and increasing patient engagement. Numerous studies analyze the effectiveness of AR/VR/MR systems, exploring approaches to increase autonomy and improve adherence in the absence of a therapist. AR/MR rehabilitation is actively being researched and tailored to various patient populations and rehabilitation objectives. AR has shown promising effects in alleviating phantom limb pain (PLP) and reversing cortical reorganization by providing visual representations of intact limbs to patients with distorted phantom limbs [23]. For lower limb amputees, existing research has primarily focused on highly immersive VR training, reporting positive effects on balance, gait, and reduction in phantom limb phenomena (PLT) [24; 25; 26]. Notably, MR systems, when combined with sEMG analysis, can contribute to monitoring muscle activity and enhancing muscle activation and training effectiveness through real-time synchronization with virtual prostheses [27]. AR technology has been proven effective in enhancing upper and lower limb functional recovery in stroke patients [11]. Low-cost solutions, such as phone-based AR systems (CARS), have shown significant effects on improving upper limb exercise and cognitive function, thereby expanding the potential for home-based rehabilitation [28]. Research actively integrates VR/AR and gamification into robot-assisted therapy to boost patient motivation and improve motor function [29]. Furthermore, AR and MR therapies have outperformed conventional treatments in terms of upper limb disability and activities of daily living (ADL) functional outcomes in stroke upper limb rehabilitation [30]. AR/VR interventions have also proven effective in hand rehabilitation, an area frequently affected by work-related hand injuries. Real-time feedback, challenging tasks, and individualized difficulty progression act as motivating factors that enhance patient adherence [31]. Rotator cuff rehabilitation games utilizing VR and motion tracking technology have also been developed and received positive preliminary evaluations [32]. A three-dimensional interactive AR system (3D-ARS) for balance and mobility rehabilitation in the elderly has demonstrated clinical efficacy, showing significant improvements in balance and mobility scales [16]. AR-based training systems can also be utilized for cognitive rehabilitation in the elderly, improving abilities such as spatial visualization and mental rotation [33]. Despite the demonstrated positive effects of AR/MR technologies across various rehabilitation domains, several critical research gaps persist. Firstly, there is still a paucity of research directly investigating the effects of AR systems on lower limb amputees, particularly studies focusing on movement accuracy and subjective satisfaction. Existing amputee rehabilitation research primarily concentrates on highly immersive VR interventions, and the specific effects of precise movement guidance and feedback offered by AR's real-world overlay characteristics have not been sufficiently explored. Secondly, there is an overall lack of high-quality randomized controlled trials (RCTs), and heterogeneity and risk of bias among studies make it challenging to conclusively determine whether AR/VR interventions are definitively superior to traditional rehabilitation [24; 34].