## 5 Discussion
### Limitations  
This study, while contributing to the understanding of AR-based rehabilitation for lower limb amputees, has several limitations that warrant consideration for future research.  
A significant limitation is the relatively small sample size, which restricts the generalizability of our findings. Within this small cohort, there was also a disproportionate representation of amputation levels, primarily consisting of transfemoral amputees (n = 9)with only one transtibial amputee. While we aimed to explore AR training applicability across lower limb amputations, this asymmetry makes it challenging to definitively conclude if observed AR training effects are equally efficacious across different amputation levels. Future research should aim for a larger, more diverse, and balanced cohort of lower limb amputees, with sufficient representation for each amputation level, to allow for robust comparisons and enhance the generalizability of findings. Additionally, developing and testing amputation-specific AR training protocols would be beneficial to address unique anatomical and biomechanical considerations.  
This study primarily investigated the short-term effects of AR training, as long-term follow-up was not conducted. Consequently, we cannot definitively determine the impact of AR training on long-term functional recovery, sustained adherence to training, or changes in quality of life. Future research should incorporate extended follow-up periods to assess the sustained benefits and long-term efficacy of AR-based interventions. Furthermore, a notable limitation is the lack of blinding, as both participants and assessors were aware of the experimental conditions. This open-label design introduces the potential for expectancy effects or subjective bias to influence the reported outcomes. Future research would benefit from implementing blinding strategies, such as using a sham control or a blinded assessor, to minimize these potential confounds and enhance the objectivity of the findings.  
This study exclusively focused on specific movements, and therefore, it did not address the full spectrum of movements necessary for the comprehensive rehabilitation of lower limb amputees. Future research should consider incorporating a broader range of functional movements and activities to provide a more holistic understanding of AR training's impact on overall rehabilitation. Additionally, this study relied on a 5-point Likert scale to assess subjective satisfaction. While useful for a general overview, this approach is somewhat simplistic and does not allow for an in-depth exploration of patients' experiences with various training modules. Future research could benefit from employing more comprehensive qualitative methods, such as semi-structured interviews or open-ended questionnaires, to gain richer insights into participants' perceptions, challenges, and preferences regarding AR-based rehabilitation.  
Given the current lack of definitive conclusions regarding the superiority of AR/VR interventions over traditional rehabilitation [24,34], there is a continuous need for high-quality randomized controlled trials (RCTs) like this study to further clarify the clinical utility of AR systems. Considering the limitations of existing research, which shows improvements in walking speed and distance but still lacks consistent evidence for balance outcomes [35], future studies should focus more on verifying the long-term and consistent effects of AR on enhancing balance ability in lower limb amputees. Future work should also explore the development of diverse AR-based training content and interaction modalities, and evaluate their comprehensive impact on patients' functional recovery and psychological well-being within real clinical settings.