## 4 Discussion
Management of upper limb dysfunction in children with cerebral palsy is particularly crucial, as effective use of the upper limb significantly influences a child's ability to engage in educational activities, participate in daily living tasks, and explore future vocational opportunities. Addressing upper limb functionality not only enhances independence but also contributes to the broader quality of life for children with CP, enabling them to better integrate into their social and academic environments [5; 6; 7; 20]. Interventions for children with CP often focus on daily activities that promote neuroplasticity, enhancing functional outcomes [11]. WBV has gained attention in CP rehabilitation, yet evidence supporting its efficacy remains limited [21]. The neuromuscular benefits of WBV, such as reduced spasticity and enhanced proprioception through tonic vibration reflexes, are promising [21; 22]. In this pilot study, both groups demonstrated reduced spasticity over time, with the lowest scores recorded at the end of the intervention, as measured by the MAS. However, the absence of statistically significant differences between the groups suggests that vibration therapy did not provide additional benefits beyond conventional physiotherapy. This result highlights the preliminary nature of this study, which was designed to assess feasibility rather than establish therapeutic efficacy. The results provide initial insights for future research, particularly regarding the design of adequately powered trials and longer intervention durations, which may yield more definitive conclusions [23]. [PERSON] et al. [24] found that side-alternating WBV improves mobility, gross motor function, body composition, muscle function, and quality of life in children with mild to moderate cerebral palsy, regardless of vibration frequency (20 Hz or 25 Hz). A 20-week program proved more effective than 12 weeks, with participants standing barefoot--closed kinetic chain (CKC)--on the vibration plate. Similarly, in our study, both groups experienced a reduction in spasticity over time, with the lowest scores observed at the intervention's conclusion. A recent systematic review and meta-analysis analyzed 16 studies on WBV combined with physiotherapy for children with CP, finding significant improvements in walking speed and step length, with positive trends in muscle strength, spasticity reduction, and stability, particularly in milder cases (GMFCS I-II). However, WBV training showed no statistically significant differences in muscle strength compared to controls [25]. Handheld vibration serves as a form of resistance training, potentially mitigating muscle weakness in the affected limb by engaging the sensorimotor system and enhancing muscle activation. Apart from musculoskeletal conditions, vibration therapy has been used to improve shoulder mobility and upper limb strength in other pathologies, such as breast cancer patients [26]. In our study, the upper body was supported through the upper limbson a vibration plate in a CKC. However, this study did not assess outcomes of UEVT-WBV related to upper limb muscle strength, core stability, or posture. The CKC approach was chosen in our study (stable vibration plate instead of hand-held vibration training) as it offers a more stable and functional training environment, promoting better muscle activation, joint stability, and neuromuscular coordination. CKC exercises increase muscle co-activation and engage the entire kinetic chain, mimicking real-life movement patterns. CKC exercises are preferred in rehabilitation for promoting functional movement and reducing joint stress. Additionally, they improve postural control, which is essential for optimizing the benefits of vibration training. [PERSON] et al. [27] evaluated the combined use of WBV training and CKC exercises for early knee osteoarthritis, showing that WBV effectively reduces pain and improves performance compared to CKC alone. Thus, a CKC approach in our study highlights its potential as a safe and functional therapeutic option. [PERSON] et al.