Mobile Apps for Foot Measurement in Pedorthic Practice: Scoping Review (Preprint)

Abstract

BACKGROUND With the public coverage of smartphones now at a global level, a major growth in the use of apps related to the health category, specifically those concerned with foot health can be observed. Although new, these apps are being used practically for scanning feet with an aim to providing accurate information about various properties of the human foot. With the availability of many ‘foot scanning and measuring apps’ in the commercial market (app stores), the need for an evaluation system for such apps can be deemed necessary as little information regarding the evidence-based quality of these apps is available. OBJECTIVE To characterize the assessment of measurement techniques and essential software quality characteristics of mobile foot measuring apps, and determine their effectiveness for potential use as commercial professional tools for foot care health professionals such as pedorthists, podiatrists, orthotists and so on, to assist in measuring foot for custom shoes, and for individuals to enhance the awareness of foot health and hygiene and prevention of foot-related problems. METHODS An electronic search across Android and iOS app stores was conducted between July 2020 and August 2020 for apps related to foot measurement. Mobile apps with stated goals of foot measurement and general foot health were identified and selected by three independent raters and discrepancies regarding the selected apps were resolved via a fourth rater. A modified rating tool based on previous works of app rating tools was adopted and extended for rating of selected apps. The internal consistency of the rating tool was tested with a group of 6 people who rated the selected app over an interval of 5-6 days. This modified scale was then used to produce evaluation scores for the selected range of foot measurement apps and the inter-rater reliability of this study was also calculated. Discrepancies found for any criteria during app reviews were discussed mutually by the raters to arrive at a unified decision. RESULTS Evaluation inferences found all apps failing to meet even half of the measurement-specific criteria required for the proper manufacturing of custom-made footwear. 23% (6/26) of apps were found to utilize either external scanners or advanced algorithms to reconstruct 3D models of user foot that can possibly be used for ordering custom-made footwear (shoes, insoles/orthoses) and medical casts for fitting irregular foot sizes and shapes. Apps had varying levels of performance and usability, with the overall measurement functionality being subpar with mean 1.97 out of 5. Apps that were linked to online shops and stores (shoe recommending) were assessed to be more usable than other foot measuring apps, but didn’t work with custom shoe sizes and shapes. Overall, current apps for foot measurement do not follow any specific guidelines for measurement purposes. CONCLUSIONS Majority of the commercial apps in app stores cannot be comprehensively evaluated as viable apps ready for use as professional tools in assisting foot care health professionals or individuals in measuring their foot for custom-made footwear purposes. Apps lack software quality characteristics that are needed for proper measurement and for providing awareness about foot health and induce motivation to prevent and cure foot-related problems. Guidelines similar to the essential criteria items in this study are needed to be developed for future apps aimed at foot measurement for custom-made or individually fitted footwear and creating awareness about foot health.