Fibromyalgia is considered a condition of unknown etiology, affecting approximately 2-5% of the population in developed countries, predominantly women, and is most commonly diagnosed between the ages of 40 and 50. Its main characteristic is the presence of widespread musculoskeletal pain. Although the most frequently reported symptoms include multiple tender points, fatigue, and cognitive dysfunction, this syndrome is also commonly associated with anxiety, depression, and pain catastrophizing.

In Chile, fibromyalgia accounts for up to 26.7% of private rheumatology consultations, with a similar scenario observed in the city of Concepción. This highlights the need to implement innovative therapeutic strategies that allow patients to practice motor and cognitive skills in various contexts, including occupational and domestic environments. In this regard, virtual reality has emerged as a promising tool for this population, as it provides a controlled virtual environment where patients can engage in different therapeutic techniques, moving beyond conventional treatment approaches.

Through this approach, interventions may include relaxation exercises, cognitive-behavioral therapy, and adapted physical activities. Such interaction may improve cognitive function, reduce symptoms of anxiety, decrease pain perception associated with the condition, and enhance overall quality of life.

This study aims to evaluate the effectiveness of a physiotherapy intervention combined with immersive virtual reality on quality of life, cognitive function, and psychological symptoms in patients diagnosed with fibromyalgia. This study corresponds to a randomized controlled crossover clinical trial in which participants will be randomly assigned to one of two groups: Group A will initiate the intervention with physical exercise using immersive virtual reality, while Group B will begin with physical exercise without virtual reality support (control condition). After completing the first intervention period, a crossover will be performed, such that Group A will continue with exercise without virtual reality and Group B will receive the immersive virtual reality intervention. In this way, all participants will experience both exercise modalities, allowing for both within- and between-subject comparisons. A washout period will be included between phases to minimize potential carryover effects. Each group will consist of 21 participants recruited from the Kinesiology Center of Universidad San Sebastián. Cognitive function will be assessed using the Montreal Cognitive Assessment (MoCA), psychological variables will be evaluated using the Depression Anxiety Stress Scales (DASS-21), and quality of life will be measured using the Fibromyalgia Impact Questionnaire-Revised (FIQ-R). All outcomes will be assessed at baseline and after each intervention phase.

This study aims to evaluate the effectiveness of a physiotherapy intervention combined with immersive virtual reality on quality of life, cognitive function, psychological symptoms, and pain perception in individuals diagnosed with fibromyalgia. Fibromyalgia is a chronic condition characterized by widespread musculoskeletal pain, fatigue, cognitive impairment, and emotional disturbances, which significantly impact patients' quality of life. Given the limitations in adherence and effectiveness of conventional rehabilitation strategies, immersive virtual reality has emerged as a promising complementary tool, allowing patients to engage in therapeutic activities within controlled, interactive environments that may enhance motivation, adherence, and clinical outcomes.

This study is designed as a randomized controlled crossover clinical trial with pre-post assessments. Participants will be randomly assigned in a 1:1 ratio to one of two sequences: immersive virtual reality exercise followed by conventional exercise, or conventional exercise followed by immersive virtual reality. Each intervention phase will last six weeks, with sessions conducted twice per week. A washout period will be implemented between phases to minimize potential carryover effects. This crossover design allows each participant to serve as their own control, enabling both within-subject and between-condition comparisons.

Participants will be adults aged 18 years or older with a medical diagnosis of fibromyalgia according to the American College of Rheumatology criteria. They will be recruited from the Kinesiology Center of Universidad San Sebastián, Concepción, Chile, as well as through community outreach and patient associations. All participants will provide informed consent prior to enrollment, and the study protocol has been approved by the Scientific Ethics Committee of Universidad San Sebastián.

The intervention will consist of a structured physiotherapy program including aerobic exercise, coordination training, and relaxation techniques. In the experimental condition, these activities will be performed using immersive virtual reality systems (Meta Oculus Quest devices), incorporating guided exercise environments designed to stimulate motor and cognitive engagement. In the control condition, participants will perform the same exercises under therapist supervision without virtual reality. This design ensures comparability between conditions while isolating the effect of the immersive component.

Outcome measures will be assessed at baseline and after each intervention phase. Primary outcomes include quality of life, measured using the Fibromyalgia Impact Questionnaire-Revised (FIQ-R). Secondary outcomes include cognitive function assessed with the Montreal Cognitive Assessment (MoCA), psychological symptoms evaluated using the Depression Anxiety Stress Scales (DASS-21), pain intensity measured with the Numeric Rating Scale (NRS), mechanical pain sensitivity assessed through pressure pain thresholds (PPT), and sleep quality measured with the Jenkins Sleep Questionnaire. Sociodemographic and clinical variables will also be recorded.

Data analysis will be conducted using appropriate statistical methods, including descriptive analysis, normality testing, and inferential comparisons between conditions and time points. Paired t-tests or non-parametric equivalents will be applied as appropriate, and effect sizes will be calculated to estimate the magnitude of changes. A significance level of p < 0.05 will be used for all analyses.

This study is expected to contribute to the understanding of the role of immersive virtual reality as a complementary therapeutic tool in fibromyalgia rehabilitation, particularly in relation to clinical outcomes, patient experience, and treatment adherence.

Inclusion Criteria:

• Adults aged 18 years or older
• Medical diagnosis of fibromyalgia according to the American College of Rheumatology (ACR) criteria
• Ability to understand and follow study instructions
• Willingness to participate and provide written informed consent

Exclusion Criteria:

• Pregnancy or breastfeeding
• Oncological pain
• Uncontrolled metabolic disorders
• History of vertigo or conditions that may be exacerbated by virtual reality use
• Any neurological or musculoskeletal condition that limits participation in exercise

Individual participant data will not be shared due to ethical and confidentiality considerations. The study involves sensitive clinical information from patients with fibromyalgia, and data will be handled in accordance with institutional ethical guidelines and data protection regulations. Access to the dataset will be restricted to the research team, and all data will be stored securely in password-protected systems. No identifiable information will be disclosed to external researchers.