Development and Psychometric Evaluation of the Arabic Version of the Motor Fitness Scale in Saudi Older Adults: A Cross-Cultural Validation Study

Background and aim: Motor fitness is a key determinant of functional independence and healthy aging in older adults. The Motor Fitness Scale (MFS) is a simple and widely used instrument for assessing mobility, strength, and balance; however, no validated Arabic version exists. This study aimed to translate, cross-culturally adapt, and evaluate the psychometric properties of the Arabic MFS in a Saudi geriatric population. Methods: This cross-sectional validation study was conducted at King Saud University Medical City (2025–2026) among adults aged ≥50 years. Structural validity was examined using confirmatory factor analysis (CFA) with a hierarchical three-factor model (mobility, strength, balance). Reliability was assessed using Cronbach’s alpha, composite reliability, and intraclass correlation coefficient (ICC). Discriminative validity was examined using logistic regression and ROC analysis. Results: A total of 140 participants (median age 60 years) were included. CFA supported the second-order three-factor model with good model fit (CFI = 0.986, TLI = 0.983, RMSEA = 0.038). Composite reliability ranged from 0.703 to 0.840 across subscales, and internal consistency was good (α = 0.842). Test–retest reliability was strong (r = 0.797; ICC = 0.831), with no systematic score differences over time. The MFS demonstrated moderate discriminative ability for physical activity status (AUC = 0.671), and higher MFS scores independently predicted physical activity (OR = 1.19, p = 0.007). Conclusions: The Arabic Motor Fitness Scale demonstrates good structural validity, internal consistency, and test–retest reliability among older adults in Saudi Arabia. The Ar-MFS is a practical and psychometrically sound instrument for assessing motor fitness and functional performance in Arabic-speaking geriatric populations.