## 2 Material and Methods
### Evaluation Timeline and Outcome Measures  
Participants were evaluated longitudinally at three time points (T0, T1, and T2) using standardized outcome measures (detailed below). The first assessment (T0--baseline) was conducted prior to the start of treatment. The second assessment (T1--before discharge) occurred at the conclusion of the initial phase of face-to-face treatment administered during hospitalization. The final assessment (T2) was conducted at the end of the second phase of treatment delivered via telemedicine (TR) (Figure 3).  
The primary outcome measure was the Melbourne Assessment 2 (MA2) [38], a tool designed to assess four key aspects of upper limb movement quality in children aged 2.5 to 15 years with neurological impairments. The four assessed aspects are: (i) Range of Movement (MA2-RM), (ii) Accuracy of Reach and Placement (MA2-ARP), (iii) Dexterity in Grasp, Release, and Manipulation (MA2-DEX), and (iv) Fluency of Movement (MA2-FM). The MA2 allows for the calculation of four separate scores, each reflecting one of these key aspects of upper limb movement quality.  
The secondary outcome measures included:  
* The Besta Scale [39];
* A subtest measuring manual dexterity from the Movement Assessment Battery for Children--MABC-2 [40];
* The Pediatric Quality of Life Inventory--Cerebral Palsy Module (PedsQL) [41].  
The Besta Scale (BS) consists of three subscales that measure the following: grasp function of the paretic hand (Besta A), spontaneous use of the paretic hand in bimanual  
Figure 3: Study design and TS-NP.  
activities (Besta B), and the use of the paretic hand in daily living activities (Besta C). Each subscale score ranges from 0 to 12, with higher scores indicating better motor performance.  
The MABC-2 is a standardized test used to assess children's motor skills, including manual dexterity, aiming and catching, and balance. In this study, we used the manual dexterity subtest, specifically the \"posting coins\" task, where children are asked to place 12 coins into a container through a slot. Both hands are tested independently. Although this subtest is designed for children aged 3-6 years to assess manual dexterity, in our study, it was used to measure the speed of the paretic limb during the task. Children performed the task only with their paretic arm, and the score was determined by the number of seconds required to complete the task.  
The PedsQL measures health-related quality of life (HRQoL) specific to cerebral palsy (CP) and has two formats: a parent-report format (P-PedsQL) that assesses parents' perceptions of their child's quality of life, and a child self-report (S-PedsQL). The PedsQL consists of seven scales: (1) Daily Activities, (2) School Activities, (3) Movement and Balance, (4) Pain and Hurt, (5) Fatigue, (6) Eating Activities, and (7) Speech and Communication. Each scale is scored from 0 to 100, with higher scores indicating a better quality of life.  
Finally, at T2, the usability of the K-VRRS was assessed using the System Usability Scale (SUS) [42]. The SUS is a ten-item scale that measures users' subjective evaluation of the usability of technological systems and devices. The total score ranges from 0 to 100, with higher scores indicating better usability. In this study, the SUS was administered to the parents of the participating children. All the scales and tests used as outcome measures have good psychometric properties [38; 39; 40; 41; 42]. Each of the different tests was administered by a different professional (neuropsychomotor specialists, physiotherapists, psychologists, and occupational therapists), all of whom routinely conduct the specific tests in standard clinical practice. However, the same test was administered to all the children by the same professional. The person administering the tests was not blind to the research protocol.