The Pluses and Minuses of Obtaining Measurements from Digital Scans

Digital scanners are commonplace and are used in many different applications to obtain three-dimensional shapes and linear and circumferential measurements. Even though scanners can be highly accurate, measurements obtained from scanners can vary depending on how an object is scanned, aligned and processed. In this study, we examined the effect of three different alignment methods of foot scans and their effects on ten different measurements. Variations among methods in capturing foot length are relatively small relative to arch length. The foot girths can be quite sensitive to the registration process depending on the complexity of the algorithms used. As expected, linear and girth measurements based on anatomical landmarks will always be independent of any registration process and are thus good ways to obtain repeatable measurements.