Motor Imagery and Action Observation for Gait Function in MS

Change in muscle activity amplitude (microvolts, µV) of tibialis anterior and gastrocnemius medialis during gait initiation measured by surface EMG.

Change in onset latency (milliseconds, ms) of tibialis anterior and gastrocnemius medialis muscle activation during gait initiation measured by surface EMG.

Change in step length (centimeters, cm) during gait initiation measured by the GAITRite system.

Change in step time (seconds, s) during gait initiation measured by the GAITRite system.

Change in step width (centimeters, cm) during gait initiation measured by the GAITRite system.

Change in double support period (percentage of gait cycle, %) during gait initiation measured by the GAITRite system.

Change in gait velocity (centimeters per second, cm/s) during gait initiation measured by the GAITRite system.

Change in cadence (steps per minute, steps/min) during gait initiation measured by the GAITRite system.

Kinesthetic and visual imagery vividness will be assessed using the Kinesthetic and Visual Imagery Questionnaire-20 (KVIQ-20), which includes 10 visual and 10 kinesthetic items (20 total). Each item is rated on a 5-point Likert scale (1 = no image/sensation, 5 = vivid image/sensation). Higher scores indicate better imagery ability.

The ratio between imagined and actual Timed Up and Go (TUG) performance time (both measured in seconds, s) will be calculated. During imagined trials, participants will press a button to mark the start and end of the imagined movement sequence. A ratio closer to 1 indicates better temporal congruence between imagined (iTUG) and executed TUG performance.

Right-left discrimination ability will be evaluated using the Recognise Foot App™ developed by the NOI Group™. Both accuracy (percentage of correct responses, %) and response time (milliseconds, ms) will be recorded.

General cognitive functioning will be screened using the Standardized Mini-Mental State Examination (SMMSE). The test is scored on a 30-point scale (0-30). Scores ≥24 indicate normal cognitive functioning.

Fatigue severity specific to MS will be measured with the Fatigue Severity Scale (FSS). The FSS consists of 9 items rated on a 7-point Likert scale (1 = strongly disagree; 7 = strongly agree). The final score is calculated as the mean of all items (range: 1-7), with higher scores indicating greater fatigue severity.

Emotional state will be assessed using the Hospital Anxiety and Depression Scale (HADS). The scale consists of 14 items divided into two subscales: anxiety (7 items) and depression (7 items). Each item is scored from 0 to 3, yielding subscale scores ranging from 0 to 21. Higher scores indicate greater levels of anxiety or depression.

Expanded Disability Status Scale (EDSS) scoring will be performed using the standardized Neurostatus-EDSS format. This scale evaluates functional systems such as motor ability, balance, vision, and sensory function to quantify disability level in individuals with multiple sclerosis. Scores range from 0 to 10 in 0.5-point increments, where 0 indicates normal neurological status and 10 represents death due to MS. Higher scores reflect greater disability.

Participants' visual acuity will be assessed using the Snellen chart under standard conditions. The test will be conducted with or without corrective lenses depending on the participant's usual visual aid usage. Visual acuity will be recorded as a Snellen fraction (e.g., 20/20, 20/40), where larger denominators indicate poorer visual performance.

The NASA Task Load Index (NASA-TLX) will be used to measure mental and physical workload related to the task. The scale consists of six subscales: mental demand, physical demand, temporal demand, performance, effort, and frustration. Each subscale is rated on a 0-100 visual analog scale, and an overall workload score is obtained by averaging the six subscales. Higher scores indicate greater perceived workload.