## 4 Discussion
Stroke rehabilitation emphasizes the active use of the affected side to prevent atrophy and promote recovery [40], suggesting that additional strategies may be needed alongside these aids to further enhance muscle activation. The higher BB activation on the PS compared to the NPS, despite reduced motor control, likely reflects compensatory strategies where stroke patients rely on gross motor movements instead of fine motor skills [33]. While the higher muscle activity observed on the PS during more complex writing tasks may seem counterintuitive, it is a logical outcome of the rehabilitation process. This increased muscle activation, particularly in the BB, reflects compensatory strategies where larger proximal muscles stabilize the arm when fine motor control is compromised [38; 41]. This heightened activity supports rehabilitation goals, encouraging the use of the affected side to improve motor control and prevent atrophy. The task-dependent variability in activation patterns, with more pronounced differences for complex movements, highlights the influence of task complexity on muscle activation and recovery. The lower TB activity on the PS with AG suggests that this aid effectively stabilizes the hand, reducing the need for triceps engagement during writing. Writing aids that stabilize the wrist and hand, like AG, help minimize reliance on extensor muscles, especially for fine motor tasks such as vowel writing [42]. However, the increased UT activation observed when writing Korean consonants on the PS indicates that complex strokes require greater posture control. The significant UT activation with AG may result from its limitation on fine motor adjustments, which could increase strain on the shoulder even during simpler tasks. In contrast, SW's broader base reduces compensatory upper body movements, leading to decreased UT engagement for such tasks. Spasticity, a frequent result of stroke-induced paralysis, contributes to heightened muscle activity on the PS during functional tasks. It increases the tone of specific muscles, particularly flexors or extensors, depending on the affected brain regions, leading to overactivity in proximal muscles like the BB and UT. These muscles are often recruited to stabilize the arm when distal muscle, such as wrist and finger flexors, are impaired. This exacerbates compensatory movements, forcing stroke patients to rely on larger muscle groups for fine motor tasks [26; 27]. Spasticity not only elevates muscle activity but also reinforces compensatory strategies, reducing motor efficiency on the PS. Rehabilitation strategies should target both spasticity and compensatory mechanisms. Specific interventions, such as targeted therapies or pharmacological treatments, can help decrease excessive muscle activity, enhancing fine motor control and the functional use of the affected limb. These findings provide valuable insights for clinical practice. For physicians, it is recommended to evaluate the individual biomechanical characteristics and hand function limitations for stroke patients when prescribing rehabilitation tools. Writing aids should be selected based on their ability to reduce compensatory movements and optimize upper extremity muscle activation, thereby improving handwriting and functional independence. For physiotherapists, the integration of writing aids into tailored rehabilitation protocols can support the recovery of fine motor skills and enhance upper extremity function. Continuous assessment of muscle activation patterns and functional outcomes, as observed in this study, is crucial for optimizing the efficacy of such interventions. By incorporating these devices into therapy sessions, physiotherapists can provide targeted support for patients, addressing their specific motor and functional impairments. There are some limitations with this study. First, this study focused on a specific population of right-handed stroke patients aged 65 and above with right-sided hemiparesis.