TMT uses traditional mirror boxes to provide the mirror visual feedback of the less affected hand during mirror therapy

MVF-MT provides real-time digital image of the less affected hand as the mirror visual feedback during mirror therapy

The Modified Ashworth Scale (MAS) will be used to assess the severity of muscle spasticity in the affected upper extremity by measuring resistance to passive movement. The MAS utilizes a 6-point ordinal scale with grades of 0, 1, 1+, 2, 3, and 4. A score of 0 indicates no increase in muscle tone, while a score of 4 indicates that the affected part is rigid in flexion or extension. The specific grade of 1+ represents a slight increase in muscle tone, manifested by a catch, followed by minimal resistance throughout the remainder (less than half) of the range of motion. Higher scores indicate greater severity of spasticity and increased resistance to passive stretch. The MAS is a widely accepted standard for evaluating spasticity in the stroke population.

The Medical Research Council (MRC) scale will be used to assess muscle strength in the affected upper extremity. This assessment utilizes a 6-point ordinal scale ranging from 0 (no visible contraction) to 5 (normal strength against full resistance). Specifically, a grade of 3 indicates active movement against gravity, while a grade of 4 indicates active movement against gravity and some resistance. Scores are assigned to specific muscle groups (e.g., shoulder abductors, elbow flexors, and wrist extensors), and the total score is calculated by summing these individual values. Higher scores indicate greater muscle strength and better motor recovery.

The Nottingham Extended Activities of Daily Living Scale (NEADL) assesses the participant's independence in instrumental activities of daily living across four domains: Mobility, Kitchen, Domestic, and Leisure. This 22-item questionnaire evaluates how often the participant has performed specific activities in the recent past. Items are scored on a 4-point scale ranging from 0 (unable to do) to 3 (able to do on one's own), yielding a total score that ranges from 0 to 66. Higher scores indicate greater independence and participation in extended daily living activities. The NEADL is a widely validated measure for assessing functional recovery and community integration in stroke survivors.

The Lawton-Brody Instrumental Activities of Daily Living Scale (IADL) assesses the participant's ability to perform eight complex activities required for independent living: using the telephone, shopping, food preparation, housekeeping, laundry, mode of transportation, responsibility for own medications, and ability to handle finances. Each item is generally scored as 0 (dependent) or 1 (independent), yielding a total score ranging from 0 to 8. Higher scores indicate greater functional independence, while lower scores suggest a need for assistance in performing daily tasks. This scale is widely used to monitor functional status and identify decline in older adults and stroke survivors.

The EuroQol 5-Dimension 5-Level (EQ-5D-5L) questionnaire will be used to assess the participant's health-related quality of life. This instrument comprises a descriptive system covering five dimensions: Mobility, Self-Care, Usual Activities, Pain/Discomfort, and Anxiety/Depression. Each dimension is rated on a 5-point ordinal scale ranging from 1 (no problems) to 5 (extreme problems/unable to perform). These responses are converted into a single utility index score based on country-specific value sets, where a score of 1 represents perfect health and 0 represents death (with negative values indicating health states considered worse than death). Additionally, the EQ-5D-5L includes a Visual Analogue Scale (EQ-VAS), where participants rate their overall health on a scale from 0 (worst imaginable health) to 100 (best imaginable health). Higher scores on both the utility index and the VAS indicate better health-related quality of life.

The Functional Abilities Confidence Scale (FACS) will be used to measure the participant's self-efficacy regarding their ability to perform various physical activities and postures. This 15-item instrument requires participants to rate their level of confidence for each specific activity on a scale ranging from 0 (no confidence) to 100 (complete confidence). The total score is calculated by averaging the ratings across all items, yielding a final score between 0 and 100. Higher scores indicate a greater level of self-confidence in functional capabilities, which is a critical psychological factor influencing rehabilitation engagement and motor recovery in stroke survivors.

The Stroke Self-Efficacy Questionnaire (SSEQ) will be used to assess the participant's confidence in their ability to perform functional activities and manage self-care tasks following a stroke. This 13-item instrument covers two main domains: activity (related to functional independence) and self-management (related to coping with stroke consequences). Each item is rated on a 4-point ordinal scale ranging from 0 (not at all confident) to 3 (very confident), yielding a total score that ranges from 0 to 39. Higher scores indicate a higher level of self-efficacy, which is associated with better functional recovery and quality of life in stroke survivors.

The Daily Living Self-Efficacy Scale (DLSES) will be used to assess the participant's confidence in their ability to function independently in daily life following a stroke. This 12-item instrument comprises two subscales: self-efficacy for activities of daily living and self-efficacy for psychosocial functioning. Participants rate their level of confidence for each specific task on an 11-point scale ranging from 0 (not confident at all) to 10 (completely confident). The total score is calculated by summing the responses, resulting in a range of 0 to 120, where higher scores indicate a greater level of self-efficacy in managing daily activities and psychosocial challenges. The DLSES is a psychometrically sound measure specifically validated for the stroke population.

The Chinese version of the Movement Imagery Questionnaire-Revised, Second Edition (MIQ-RS) will be used to evaluate the participant's ability to perform visual and kinesthetic motor imagery. This 14-item instrument comprises two subscales: Visual Imagery (7 items) and Kinesthetic Imagery (7 items), covering movements of the upper and lower extremities as well as the trunk. For each item, the participant first physically executes a movement and then imagines performing it, rating the ease or difficulty of the mental image on a 7-point Likert scale ranging from 1 (very hard to see/feel) to 7 (very easy to see/feel). The total score ranges from 14 to 98, with subscale scores ranging from 7 to 49. Higher scores indicate superior motor imagery ability. The Chinese version of the MIQ-RS has demonstrated good reliability and validity specifically for the stroke population.

The Embodiment Questionnaire will be used to evaluate the participant's subjective experience of embodiment towards the virtual or assisting limb during the intervention. This assessment specifically measures two primary domains: Sense of Ownership (the feeling that the virtual/observed limb belongs to the user) and Sense of Agency (the feeling that the user is generating and controlling the movements). Participants rate their agreement with a series of statements on a 7-point Likert scale ranging from 1 (strongly disagree) to 7 (strongly agree), or alternatively from -3 to +3 depending on the specific adaptation used. The scores are averaged for each domain, with higher scores indicating a stronger sense of embodiment, which is hypothesized to facilitate motor learning and neural reorganization in stroke rehabilitation.

Electroencephalography (EEG) will be used to assess cortical activation by measuring the Event-Related Desynchronization (ERD) of the sensorimotor mu rhythm (typically 8-13 Hz). Signals will be recorded from electrodes positioned over the sensorimotor cortex (e.g., C3 and C4 according to the international 10-20 system). ERD is calculated as the percentage decrease in the spectral power of the mu band during motor tasks relative to a resting baseline period, using the formula: (Task Power - Baseline Power) / Baseline Power × 100. The resulting values are expressed as percentages, where a more negative value (indicating greater suppression of the mu rhythm) reflects higher cortical excitability and engagement of the motor system during the task.

Surface Electromyography (sEMG) will be used to assess the functional coupling between motor units of the wrist extensor muscles through the analysis of Intermuscular Coherence (IMC). sEMG signals will be recorded during dynamic wrist extension tasks. IMC is calculated in the frequency domain, typically focusing on the beta band (15-30 Hz), to quantify the strength of common neural drive to the muscle pair, with values ranging from 0 (no coherence) to 1 (perfect coherence). Higher coherence values in the beta band generally indicate stronger corticospinal coupling and more synchronized motor unit firing, which are associated with better motor control and recovery following stroke.