This single-center interventional study aims to develop and validate a static balance assessment tool tailored for high-functioning older adults. Participants aged 65 years or older, who achieve a perfect score on the Short Physical Performance Battery and can maintain an open-eyes single-leg stance for at least 10 seconds, will be recruited. The assessment includes body composition measurement, open-eyes/closed-eyes single-leg stance, and the Balance Error Scoring System under firm and foam surface conditions. Each participant will undergo two testing sessions, 5-7 days apart, with both on-site and video-based scoring to determine test-retest reliability. The expected outcome is the development of an accurate and highly applicable static balance measurement tool to support healthy aging and fall prevention in community and long-term care settings.

The study is conducted at Kaohsiung Municipal United Hospital, Taiwan, with the objective of creating a static balance assessment tool specifically designed for older adults who are physically high-functioning. Traditional balance tests, such as the open-eyes single-leg stance with a 30-second limit, often produce ceiling effects in this population, making it difficult to detect subtle differences in balance ability or evaluate the benefits of exercise programs. To address this limitation, the current study extends the open-eyes single-leg stance to a maximum of 60 seconds and incorporates a closed-eyes condition to increase task difficulty.

In addition, the Balance Error Scoring System, originally developed for concussion assessment, will be adapted for older adults. Balance Error Scoring System testing will be conducted under six conditions: double-leg stance, tandem stance, and single-leg stance, each performed on both firm and foam surfaces with eyes closed. This design simulates balance challenges encountered in daily life while minimizing fall risk.

Eligible participants (n=50) will be community-dwelling older adults aged ≥65 years, with perfect Short Physical Performance Battery scores and no recent lower limb injuries or neurological conditions. Each participant will complete two identical assessment sessions, spaced 5-7 days apart. Both on-site evaluators and independent assessors reviewing video recordings will score performance. The primary outcome is the test-retest reliability of each balance measure, quantified through statistical analysis.

The anticipated benefit of this study is to establish a reliable, sensitive, and practical balance assessment protocol that can be implemented in community health programs, long-term care facilities, and research settings. This tool aims to improve early detection of balance decline, guide intervention planning, and ultimately contribute to fall prevention and healthy aging initiatives in aging societies.

Inclusion Criteria:

• Age 60 to 85 years
• Able to walk independently without assistive devices
• No self-reported balance disorders or history of recurrent falls in the past 6 months
• Cognitively intact (Mini-Mental State Examination score ≥ 24)
• Willing and able to provide informed consent

Exclusion Criteria:

• Diagnosed neurological disorders affecting balance (e.g., Parkinson's disease, stroke with residual deficits)
• Diagnosed neurological disorders affecting balance (e.g., Parkinson's disease, stroke with residual deficits)
• Severe visual or vestibular impairment uncorrected by aids
• Lower limb musculoskeletal disorders that limit mobility
• Current participation in other interventional clinical trials
• Unstable cardiovascular conditions (e.g., uncontrolled hypertension, recent myocardial infarction)
• Severe visual or vestibular impairment uncorrected by aids
• Lower limb musculoskeletal disorders that limit mobility
• Current participation in other interventional clinical trials
• Unstable cardiovascular conditions (e.g., uncontrolled hypertension, recent myocardial infarction)

No individual participant data (IPD) will be shared. The decision is based on institutional policy and the need to protect participant privacy and confidentiality. Only aggregated results will be reported in publications.

Outcome assessors who review video recordings will be blinded to the on-site assessment results to reduce scoring bias.