## 4 Discussion  
In this pilot study, we implemented a TS-NP combined with K-VRRS in children with unilateral spastic cerebral palsy (CP) to examine its effects on upper limb motor functions. Specifically, we investigated the impact of intensive motor treatment with K-VRRS, administered alongside standard physiotherapy during hospitalization, and the importance of continuing maintenance treatment with K-VRRS via tele-rehabilitation (TR) at home after discharge. To date, only a few case studies have explored the effectiveness of K-VRRS for younger populations. One study reported improvements in posture and balance in a 17-year-old female with myopathy and moderate intellectual disability following K-VRRS treatment via telerehabilitation [43]. More recent findings demonstrated enhanced motor functions in a 13-year-old girl with spinal muscular atrophy after K-VRRS-based telerehabilitation [44]. Additionally, another investigation documented a reduction in upper limb motor impairments in children with congenital hemipgesia when combining traditional physiotherapy with K-VRRS interventions during in-person rehabilitation sessions [45]. In summary, only two single-case studies have used K-VRRS in telerehabilitation mode [43; 44] and only one study implemented a rehabilitation program that used VRRS during in-person sessions conducted at the rehabilitation center [45]. Our findings suggest that intensive K-VRRS treatment during hospitalization, combined with standard physiotherapy, improves motor functions of the affected upper limb in children with unilateral spastic CP. These improvements, observed in measures such as range of movement and movement fluency (as assessed by MA2), indicate that such an inpatient treatment regimen positively influences motor function. However, the continuation of K-VRRS treatment via TR post-discharge did not result in further functional improvements beyond those achieved during hospitalization. Nonetheless, TR was crucial for maintaining the gains made during inpatient treatment, as evidenced by better motor function outcomes at the T2 assessment compared to the initial T0 assessment. While the improvement in motor function from T0 to T1 highlights the benefits of inpatient K-VRRS treatment, the lack of significant changes between T1 and T2 suggests that post-discharge TR may primarily serve a maintenance role rather than driving further enhancements. It is worth noting that the number of TR sessions in our study was relatively low, which may have limited its effectiveness. Future studies might explore whether increasing the frequency of TR sessions could yield further motor improvements in children with CP, as other research has indicated [43]. Regarding the impact of TS-NP on quality of life, we found a statistically significant increase in certain PedsQL measures, suggesting that the TS-NP approach used in this study improved parents' perceptions of their child's quality of life. Additionally, the usability of the K-VRRS system was rated positively, with a mean SUS score of 72.5, indicating good usability in line with [PERSON] et al. [46]. We did not observe statistically significant changes in secondary motor outcome measures such as the \"posting coins\" sub-test and the BESTA scale. The lack of improvement in the \"posting coins\" sub-test could be due to the fact that this task involves several fine motor, visuospatial, and visual-motor coordination skills, which were not directly targeted by our intervention. Although the BESTA scale scores did not show significant changes over time, we found a marginally significant increase in the BESTA B score, suggesting that K-VRRS-based treatment may enhance the spontaneous use of the paretic hand in bimanual activities. Further research with larger sample sizes is needed to confirm these findings and potentially identify significant improvements in BESTA scale scores following K-VRRS treatment.