Development and psychometrics of safety shoes design evaluation questionnaire based on ergonomic principles

BackgroundSafety shoes are crucial for worker protection; however, their design and ergonomics aspects have been largely overlooked.ObjectiveThis study aimed to develop and validate a questionnaire to evaluate safety shoe design issues systematically.MethodsA 35-item questionnaire was developed in this cross-sectional study. Twenty-four experts in ergonomics, HSE, and shoe production fields evaluated the questionnaire for face and content validity. The reliability of data collected from 225 participants was examined using Cronbach's alpha, the Intraclass Correlation Coefficient (ICC), and test-retest methods. Varimax-rotated principal component analysis was employed to assess construct validity through exploratory factor analysis.ResultsThe experts provided feedback during face validity, which led to changes in specific questions, yielding an average Impact Score of 4.72. The CVR was 0.91. The mean CVI for relevance, clarity, simplicity, and overall content was 0.98, 0.96, and 0.98, respectively, resulting in an overall CVI of 0.97. Factor analysis revealed Cronbach's alpha values of 0.828 for satisfaction, 0.565 for quality, 0.898 for comfort, and 0.70 for fit. The ICCs were 0.85 for fit, 0.85 for satisfaction, 0.86 for comfort and 0.759 for quality. After revisions, researchers finalized the questionnaire with 35 items.ConclusionsThe developed questionnaire demonstrated acceptable validity and reliability. This tool can identify and address design deficiencies in safety shoes (e.g., fit, comfort, quality, and satisfaction), thereby contributing to improved worker comfort and foot health. Furthermore, the instrument provides a standardized framework for future research on various types of footwear.