The Design and Validation of a Low-Cost Foot Measurement System

Abstract

It is estimated that approximately 40% of the population suffers from abnormal foot posture, specifically high arched or low arched feet. While the evaluation of foot posture can involve many aspects, it commonly requires the measurement of basic dimensions of the foot. Clinicians and researchers often rely on the use of specialized devices or 3D scanners to evaluate specific aspects of a patient's foot posture. However, current technologies are extremely expensive, therefore highlighting the need for a cost-effective device to be used in rural and clinical settings. Therefore, the purpose of this study was to develop an inexpensive system to measure total foot length, truncated length, dorsum height, navicular height, and foot width. Bland-Altman plots showed significant differences between this measurement system and a 3D scanner for total foot length, truncated length, and navicular height (p<0.001) and significant differences when assessing the repeatability of dorsum height (p=0.022). However, interclass correlation coefficients revealed that this system had excellent validity when compared to a 3D scanner (ICC = 0.908-0.994), and good to excellent repeatability when compared between days (ICC = 0.867-0.996). These results demonstrate that it is possible to design an inexpensive, valid, and repeatable system that can be used in clinical, research, and rural settings to successfully evaluate basic dimensions of the foot that can be used for the determination of foot type.

OptiFit: Computer-Vision-Based Smartphone Application to Measure the Foot from Images and 3D Scans

“…In [ 53 ], a foot-shape feature parameter measurement algorithm using a second-generation Kinect was implemented, and the authors measured foot length, foot width, metatarsal girth, and other foot parameters using a 3D foot depth image. Dickerson and Queen [ 54 ] suggested a custom-built, inexpensive foot posture measurement system (FPMS) that showed valid and accurate results compared to a 3D scanner.…”

Validation of an Automated Optical Scanner for a Comprehensive Anthropometric Analysis of the Foot and Ankle

“…They offer fast acquisition speed, user-friendly features, and improved accuracy compared to conventional methods [ 3 , 4 , 5 , 6 , 7 ]. Moreover, 3D scanners provide the possibility to measure several anthropometric parameters, which would be highly time consuming with standard methods [ 4 , 8 , 9 , 10 , 11 ].…”

“…This new technology has been associated with more reliable anthropometric measurements than conventional methods [ 4 ]. Key features of this new technology included swift acquisition, high accuracy, user-friendly interfaces, and relatively low costs [ 11 ]. Scanner analysis has allowed the characterization of the shape and size of large series of feet, whether in adults [ 12 ] or in children [ 13 ], and played an important role in confirming gender differences in foot sizes [ 14 ].…”