## 4 Discussion
These activities are most effective when they involve high repetition and are tailored to an individual's specific needs, allowing for the patient's active participation in the rehabilitation process (National Clinical Guideline for Stroke, 2023) [48]. The importance of patient-driven activities in stroke rehabilitation suggests that interventions should not only be guided by healthcare professionals but also encourage self-practice and active involvement in therapeutic activities to maximize recovery outcomes. In the results of this study, in which varying degrees of stroke severity demonstrated different responses to shaking device interventions, it is important to consider the influence of initial impairment severity on rehabilitation outcomes. This differential response aligns with previous findings in stroke rehabilitation, suggesting that the initial severity of motor function impairment can significantly dictate the potential and rate of functional recovery [16, 46]. Severe and mild cases often present with distinct challenges. Severe cases may involve extensive neurological damage, which limits the efficacy of peripheral stimulation interventions, as the central pathways may be too impaired to translate peripheral sensory inputs into meaningful motor outputs. Mild cases, on the other hand, may not show dramatic improvements simply because their baseline function is already high, and the ceiling effect limits observable changes [49]. These observations underscore the necessity for a stratified approach to treatment and tailoring interventions to match the severity of impairment. Understanding and integrating severity-specific responses into rehabilitation protocols can optimize recovery trajectories and ensure that each patient receives the most appropriate and effective intervention tailored to their needs [50]. The intervention group in our study exhibited a mean increase in FMA-UE scores; however, these gains did not surpass the minimum clinically important difference (MCID) threshold [51]. The use of a shaking device represents a novel approach that provides specific neuromuscular stimulation, which may not be traditionally targeted in conventional stroke rehabilitation. Although neuroplasticity can still be promoted in the chronic phase of stroke recovery, the extent to which it can be influenced is often constrained by the severity and location of brain injury. Consequently, even modest improvements in the FMA-UE scores could indicate beneficial neurological adaptations [2, 13]. The concept of MCID is critical for assessing the efficacy of interventions. However, it is inherently a population-based measurement that may not capture subtle yet clinically meaningful improvements at the individual level. Future studies should consider a personalized approach to therapy, emphasizing prolonged intervention durations and comprehensive outcome measures to fully capture the benefits of rehabilitation interventions. While our study did not include a placebo device control group, the potential for a placebo effect remains a consideration. The belief in the efficacy of the rehabilitation advice provided in a clinical setting might lead patients to use their affected limbs more frequently, thus contributing to functional improvements. This psychological boost, stemming from trust in the treatment and increased engagement in rehabilitation activities, could enhance outcomes independently of the mechanical benefits of the device. Future studies should consider ethical and practical ways to incorporate placebo controls to better isolate the therapeutic effects of such interventions. This study, while innovative in its approach to post-stroke rehabilitation, has several limitations. First, a key limitation of this study was the relatively small sample size, which might limit the generalizability and robustness of our findings. Our post hoc power analysis indicated a lower statistical power, suggesting that the study was underpowered to detect small to moderate effects.