Immersive Virtual Reality Program in Down Syndrome (IN DOWN)

Eksperimentel: RVI_E_Immersive Virtual Reality Exergame

Participants will complete a 12-week immersive virtual reality (VR) intervention based on high-intensity, gamified physical exercise, with two (2) supervised sessions per week. The program will take place in a controlled environment within the participants' center's gym and will be supervised by fitness and health professionals.

Adfærdsmæssigt: RVI_Experimental_Immersive Virtual Reality Exergame

Participants assigned to the experimental group wil complete a 12-week immersive virtual reality (IVR) intervention based on high-intensity gamified physical exercise, with two (2) supervised sessions per week. The program will be conducted in a controlled environment within the participants' center gym and will be supervised by exercise and health professionals.

The exergames used will be:

Beat Saber (Beat Games) (6 sessions): Participants perform upper-limb and whole-body movements by hitting virtual targets in time with music, promoting coordination, reaction time, and cardiovascular fitness.

FitXR (14 sessions): A virtual reality training program based on high-intensity interval training (HIIT), boxing, and functional movement exercises. It enhances cardiovascular endurance, motor coordinat and cognitive engagement through structured tasks with progressively increasing difficulty levels. Alcove VR (1 session): Used as an initial familiarization and adaptat

Placebo komparator: RVI_ControGroup_Immersive Virtual Reality Exergame

Participants will complete a 12-week immersive virtual reality (VR) intervention based on high-intensity, gamified physical exercise, with one (1) supervised sessions per week. The program will take place in a controlled environment within the participants' center's gym and will be supervised by fitness and health professionals.

Adfærdsmæssigt: RVI_ControGroup_Immersive Virtual Reality Exergame

Participants assigned to the experimental group wil complete a 12-week immersive virtual reality (IVR) intervention based on high-intensity gamified physical exercise, with one (1) supervised sessions per week. The program will be conducted in a controlled environment within the participants' center gym and will be supervised by exercise and health professionals. The exergames used will be: Beat Saber (Beat Games) (3 sessions): Participants perform upper-limb and whole-body movements by hitting virtual targets in time with music, promoting coordination, reaction time, and cardiovascular fitness. FitXR (FitXR Ltd., London, UK) (7 sessions): A virtual reality training program based on high-intensity interval training (HIIT), boxing, and functional movement exercises. It enhances cardiovascular endurance, motor coordinat and cognitive engagement through structured tasks with progressively increasing difficulty levels. Alcove VR (1 session): Used as an initial familiarization and adaptat

1. Assessment body composition

Description: Body composition was assessed using the Tanita MC-780 bioelectrical impedance analyzer. Measured variables included fat mass (FM), fat-free mass (FFM), muscle mass (MM), total body water (TBW), and segmental body composition of the trunk and limbs.

Unit of Measurement:

Fat Mass (FM): kg Fat-Free Mass (FFM): kg Muscle Mass (MM): kg Total Body Water (TBW): kg Segmental Body Composition: kg

Interpretation: Higher FFM, MM, and TBW indicate better physical fitness. Lower FM indicates better body composition.

Assessment usability

1. System usability will be assessed using the System Usability Scale (SUS), a validated 10-item questionnaire. Scores range from 0 to 100, with higher scores indicating better usability.

Unit of Measure:

SUS score (0-100)

Interpretation:

Scores ≥68 indicate acceptable usability; scores >80 indicate excellent usability.

Cognitive parameters: Executive function

Description: Clock Drawing Test (CDT) Participants are asked to draw an analog clock and set the hands to a specified time. Performance is scored using methods such as TRO and TCR, which evaluate the accuracy and organization of the drawing.

Unit of measurement

Total CDT score (scoring scale) ( 0-20 points)

Interpretation

Higher scores: better cognitive performance, particularly in executive and visuospatial functions Lower scores: possible impairment in planning, spatial organization, and other cognitive functions

Assessment Aerobic endurance

2-Minute Step Test Participants march in place for 2 minutes, raising their knees to a specified height. The total number of correctly completed steps is recorded.

Unit of measurement Number of steps completed in 2 minutes Interpretation Higher scores: better aerobic capacity and physical fitness Lower scores: reduced endurance and lower cardiorespiratory fitness

Health-related quality of life

Description:

Health-related quality of life will be assessed using the KidsLife-Down Questionnaire, a validated instrument for individuals with Down syndrome that evaluates eight domains of quality of life and provides standardized scores and percentiles.

Unit of Measure:

KidsLife-Down total standardized score (scale)

Interpretation:

Higher scores indicate better quality of life and well-being. Lower scores indicate greater limitations in quality of life and daily functioning.

Assessment Safety and cybersickness symptoms

Safety and cybersickness symptoms will be assessed using the Simulator Sickness Questionnaire (SSQ). Higher scores indicate greater severity of cybersickness symptoms.

Unit of Measure:

SSQ total score

Interpretation:

Lower scores indicate better tolerability and safety; a score of 0 indicates no symptoms.

Assessment user experience and engagement

User experience and engagement will be assessed using the Game Experience Questionnaire (GEQ - Post-Game Module). Items are rated from 0 to

Unit of Measure:

GEQ subscale scores (0-4)

Interpretation:

Higher scores indicate better experience for positive dimensions and poorer experience for negative dimensions.

Cognitive parameters: processing speed

Description: Symbol Digit Modalities Test (SDMT) Participants match symbols to corresponding numbers using a reference key and complete as many correct pairings as possible within a time limit.

Unit of measurement

Number of correct responses (raw score)

Interpretation

Higher scores: better attention, faster processing speed, and higher cognitive efficiency Lower scores: reduced attention, slower processing speed, and poorer cognitive performance

Assessment Dynamic balance

Timed Up and Go (TUG) Test The participant stands up from a chair, walks a set distance (usually 3 meters), turns, walks back, and sits down. The total time is recorded.

Unit of measurement Seconds (time to complete the test) Interpretation Lower times: better mobility, balance, and functional performance Higher times: impaired mobility, poorer balance, and increased risk of falls

Assessment Upper body muscular strength

Handgrip Strength (Jamar Dynamometer)

Participants squeeze a Jamar hand dynamometer with maximum voluntary force, usually with the dominant hand or both hands depending on protocol.

Unit of measurement

• Kilograms (kg) Interpretation
• Higher values: greater muscular strength and better physical condition
• Lower values: reduced strength and poorer physical fitness

Assessment Lower limb strength

Five Sit to stand Test (5STS) Participants perform five full squats as quickly and safely as possible. The total time to complete the five repetitions is recorded.

Unit of measurement Seconds (time to complete 5 squats) Interpretation Lower times: greater lower limb strength and better functional capacity Higher times: reduced strength and poorer functional performance