Objective assessment of mobility, balance, and lower extremity function in older adults is of great importance in both clinical practice and scientific research. For this purpose, performance-based tests that can be administered in a short time, are easily repeatable, and have high clinical practicality are widely preferred. These tests provide valuable information about older adults' ability to perform activities of daily living, levels of functional independence, and risk of falls, thereby contributing significantly to both diagnostic processes and treatment planning.

One of these tests, the 4-Meter Walk Test (4MWT), is among the simplest and most reliable methods used to assess walking speed in older adults. Gait speed is considered a strong indicator of functional capacity and overall health status in older individuals and is also used as a critical parameter for predicting mortality, morbidity, hospitalization rates, and duration of independent living. Therefore, due to its short administration time, high repeatability, and clinical validity, the 4MWT has become one of the standard assessment tools in the field of geriatrics.

Another frequently used assessment tool, the Five-Times Sit-to-Stand Test (5xSTS), is based on measuring the time required for an individual to consecutively stand up from and sit down on a chair five times. This test is closely associated with lower extremity muscle strength, functional independence, and the ability to maintain activities of daily living. In addition, the 5xSTS test is an important clinical tool for identifying muscle weakness and mobility limitations in older adults with a history of falls. Owing to its short administration time, lack of requirement for specialized equipment, and ease of understanding, it is widely used in both clinical settings and field studies.

In addition, the Timed Up and Go (TUG) test is considered one of the gold standard methods for the assessment of functional mobility. The test is simple to administer: the time required for an individual to stand up from a chair, walk a specified distance, turn around, and return to sit down is measured. The TUG test not only assesses mobility but is also a reliable and valid method for predicting balance impairments and fall risk. Given that falls represent a major health concern in older adults, data obtained from the TUG test provide valuable guidance for both clinicians and researchers.

In recent years, virtual reality (VR)-based assessment methods have attracted increasing attention due to their potential to provide a safe, motivating, and standardized environment, particularly for older adults. In this study, the Meta Quest 3 virtual reality headset and controllers will be used to implement VR-based functional tests. The Meta Quest 3 device features a resolution of 2064 × 2208 pixels per eye, a maximum refresh rate of 120 Hz, and a six-degrees-of-freedom (6 DoF) inside-out tracking system. The device tracks participants' head and body movements in real time and accurately reflects them within the virtual environment. This system does not require external sensors and automatically provides positional tracking in the virtual space. Previous studies have demonstrated that VR applications can produce valid and reliable outcomes when used as digital adaptations of functional tests. However, the validity and reliability of VR adaptations of the 4MWT, 5xSTS, and TUG tests in older adults have not yet been systematically investigated.

The rationale of this study is to determine whether VR-based short performance tests can serve as a safer, more easily repeatable, and potentially more accessible alternative to conventional clinical assessments. The findings of this study are expected to provide important evidence supporting the use of VR technology in clinical practice for the assessment of mobility and balance in older adults.

Inclusion Criteria:

• Aged 65 years or older,
• Ability to ambulate independently (assistive devices permitted),
• Cognitive ability sufficient to communicate and follow instructions,
• Provision of written informed consent.

Exclusion Criteria:

• Acute cardiopulmonary disease,
• Uncontrolled hypertension,
• History of lower extremity surgery or fracture within the past 6 months,
• Severe cognitive impairment preventing cooperation with testing procedures,
• Determination by a healthcare professional that participation is unsafe for safety-related reasons.

Community-dwelling adults aged 65 years and older who are able to ambulate independently (with or without assistive devices) and can communicate and follow test instructions.