Development and evaluation of a tool for the assessment of footwear characteristics

Background: Footwear characteristics have been linked to falls in older adults and children, and the development of many musculoskeletal conditions. Due to the relationship between footwear and pathology, health professionals have a responsibility to consider footwear characteristics in the etiology and treatment of various patient presentations. In order for health professionals and researchers to accurately and efficiently critique an individual's footwear, a valid and reliable footwear assessment tool is required. The aim of this study was to develop a simple, efficient, and reliable footwear assessment tool potentially suitable for use in a range of patient populations. Methods: Consideration of previously published tools, other footwear related literature, and clinical considerations of three therapists were used to assist in the development of the tool. The tool was developed to cover fit, general features, general structure, motion control properties, cushioning, and wear patterns. A total of 15 participants (who provided two pairs of shoes each) were recruited, and assessment using the scale was completed on two separate occasions (separated by 1 - 3 weeks) by a physiotherapist and a podiatrist on each participant's dominant foot. Intra-rater and inter-rater reliability were evaluated using intra-class correlation coefficients (ICCs) (model 2, 1) and the 95% limits of agreement (95% LOAs) for continuous items, and percentage agreement and kappa (kappa) statistics for categorical items. Results: All categorical items demonstrated high percentage agreement statistic for intra-rater (83 - 100%) and inter-rater (83 - 100%) comparisons. With the exception of last shape and objective measures used to categorise the adequacy of length, excellent intra-rater (ICC = 0.91 - 1.00) and inter-rater reliability (ICC = 0.90 - 1.00) was indicated for continuous items in the tool, including the motion control properties scale (0.91 - 0.95). Conclusion: A comprehensive footwear assessment tool with good face validity has been developed to assist future research and clinical footwear assessment. Generally good reliability amongst all items indicates that the tool can be used with confidence in research and clinical settings. Further research is now required to determine the clinical validity of each item in various patient populations.