Validation of a 3D foot scanning system for evaluation of forefoot shape with elevated heels

Abstract

The toe box design is a crucial element for footwear comfort in high-heeled shoes. Their shoe lasts, however, are developed based on foot measurements taken under a foot-flat condition. There lacks investigations on whether the forefoot shape changes with elevated heels. In this study, we have developed a rapid 3D foot scanning system to acquire 3D foot anthropometric measurements of elevated heels. The system's repeatability and accuracy are validated. Foot scanning is then performed on 45 female subjects in three conditions: foot-flat (0 cm), elevated mid-heel (5 cm) and high-heel (10 cm). Eighteen forefoot measurements are extracted to evaluate the changes in the forefoot shape. Our newly developed system is proven to be highly repeatable (±0.5 mm) and adequately accurate (±0.8 mm) to carry out foot anthropometric measurements. We find that with increases in heel height, the fourth and fifth metatarsal-phalangeal joints will be raised and the small toe will migrate towards the lateral side.