Translation, Cultural Adaptation, and Turkish Validation of the Tool 25-Question Geriatric Locomotive Function Scale

Abstract

Background: The increasing prevalence of locomotive syndrome (LoS) among older adults underscores the necessity of valid and reliable assessment tools to facilitate early diagnosis and intervention. The 25-Question Geriatric Locomotive Function Scale (GLFS-25) is a widely used self-reported measure for evaluating locomotive dysfunction. However, a culturally adapted and validated version for Turkish older adults was lacking. This study aims to translate, culturally adapt, and validate the Turkish version of GLFS-25 to ensure its applicability in clinical and research settings. Methods: A cross-sectional study was conducted with 133 community-dwelling older adults (mean age: 75.3 +/- 7.2 years) in Turkey. The translation process followed international guidelines, including forward-backward translation, expert panel review, and pilot testing. The psychometric validation involved confirmatory factor analysis (CFA), internal consistency (Cronbach's alpha), test-retest reliability (intraclass correlation coefficient, ICC), and criterion validity. Correlations with established functional assessment tools such as the Barthel Daily Living Index, Instrumental Activities of Daily Living (IADL), and Activities-Specific Balance Confidence (ABC) Scale were examined. A receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cut off score for detecting locomotive dysfunction. Results: The Turkish GLFS-25 demonstrated excellent internal consistency (Cronbach's alpha = 0.984) and test-retest reliability (ICC = 0.986). CFA confirmed a four-factor structure, similar to previous adaptations in Iran and China, supporting its construct validity. Strong correlations were observed between GLFS-25 scores and functional assessment tools (Barthel Index: r = -0.78, IADL: r = -0.72, ABC Scale: r = -0.65, p < 0.001), establishing its criterion validity. ROC analysis identified a cut off score of 16 for detecting locomotive dysfunction, with a sensitivity of 85.3% and specificity of 88.7%. Conclusions: The Turkish adaptation of GLFS-25 is a valid, reliable, and culturally appropriate tool for assessing locomotive dysfunction in Turkish older adults. Its strong psychometric properties and high correlation with functional mobility indicators suggest that it can be effectively integrated into geriatric healthcare and rehabilitation programs. Given the rapid aging of Turkey's population, this tool can support early detection, prevention strategies, and policy development to mitigate mobility-related disabilities.