Development and validation of the Physical Capacity Score (PiC) to overcome the lack of correlation among traditional physical tests in detecting age-related decline.

The Physical Capacity Score platform demonstrated good repeatability for most variables, with all outcomes showing coefficient of variation below 10% and intraclass correlation coefficient above 0.90, except for CoP path length.

• All variables demonstrated COV <10% and ICC >0.90 in test-retest analysis
• CoP path length was the exception with COV = 10.5% and ICC = 0.64
• The platform uses custom-built hardware and software enabling automated data collection and analysis

Correlations among physical capacity outcomes were weak across all pairwise comparisons.

• Pearson's correlation coefficient (r) range was 0.036–0.373 among all outcomes
• The weak correlations indicate low redundancy among the six physical tests
• Six tests assessed were: finger tapping, handgrip strength, single-leg stance, sit-and-reach, five-times sit-to-stand, and the YMCA 3-minute step test

All physical capacities declined significantly with age, but the magnitude of age-related decline varied considerably across different physical tests.

• All age-related differences were statistically significant (p < 0.001)
• Handgrip strength showed the smallest age-related effect (η² = 0.035)
• Sit-and-reach flexibility showed η² = 0.050; finger tapping η² = 0.059; CoP path length η² = 0.095; lower-limb power η² = 0.148
• Cardiorespiratory fitness showed the largest age-related effect (η² = 0.389)
• Outcome data were standardized by gender using z-scores and analyzed across age groups using ANOVA

The average Principal Component Analysis component scores revealed large age-related differences across the full battery of physical tests.

• The average PCA component scores showed η² = 0.301 for age-related differences
• This effect size was larger than any single individual test outcome except cardiorespiratory fitness (η² = 0.389)
• PCA was conducted to explore relationships between different physical capacities

The study recruited a sample of 812 adults spanning a wide age range, with a majority of female participants.

• Total sample: 812 participants
• Age range: 18–68 years
• 63.5% of participants were female
• Participants completed six standardized physical tests administered through the custom platform