Clara Solves Camallonga, Juan Carlos González García, Sara Gil Mora, Alfredo Ballester Fernández, Jorge Valero Zorraquino, Beatriz Nácher Fernández, Sandra Alemany Mut

Instituto de Biomecánica (IBV) Universitat Politècnica de València (Edificio 9C) Camino de Vera s/n (E-46022) Valencia (Spain)

 

To be considered reliable, a shoe size recommendation system must be based on the fit or relationship between the inner shape of the shoe and the shape of the foot. Accurate 3D scanning of the foot and the generation of statistical models for predicting fit are crucial in this respect. If the technology is to be transferred to companies, it must be scalable and able to integrate seamlessly into their business model.
The Instituto de Biomecánica (IBV) has the technology and tools to scan the user's foot and to use this information to select the model and size of footwear that best fits each user. It also makes it possible to determine the anatomy of the insole that best suits the shape of the foot.
IBV has collaborated with BASE PROTECTION and has granted a license to the company to use its 3D Avatar Feet/IBV app which captures the shape of the foot with only 3 photos. It has also adapted the algorithms that make it possible to determine the size of the footwear that best fits each user, as well as the most suitable insole for each user according to their plantar anatomy.

INTRODUCTION

When purchasing a pair of shoes, making sure that they fit properly is the key to obtaining maximum comfort. According to various studies by the Institute of Biomechanics (IBV), fit can have a more than 80% impact on comfort. Shoe fit is a very complex issue however, as each shoe company offers a different fit depending on the style of the shoe, which has to do with how it is built, the materials used, the fastening system, etc., and also the target audience.

On the other hand, people’s feet come in all shapes and sizes. Even in the case of feet of the same length, the other dimensions of the foot can vary greatly (Figure 1). This makes it very difficult for users to find the model and size of footwear that provides them with a proper fit, which discourages them from buying online and also involves significant costs for companies due to high return rates associated with an inadequate fit.

BASE PROTECTION S.R.L., a manufacturer of safety footwear, is aware of the importance of fit and comfort in safety footwear. This is why the company has integrated IBV technology for recommending the model and size of the footwear, as well as the anatomy of the insole. This integration has included:

• Technology to scan the foot in 3D. IBV offers accessible, easy to use and accurate technology that makes it possible to obtain a 3D model of the foot from just three photos taken with a mobile phone or with a simple point-of-sale device.

• Statistical modelling of foot/shoe interaction. The statistical model uses key foot shape parameters for fitting, in addition to such traditional measurements as foot length or width (Figure 1).

Figure 1. Morphological variation in feet of the same length

DEVELOPMENT AND IMPLEMENTATION

The product recommendation system was integrated into BASE PROTECTION by means of a license for the 3D foot shape acquisition technologies and the adaptation of the footwear and insole recommendation algorithms.

Transfer of 3D foot scanning technologies

The fact that the IBV has two complementary technological solutions for obtaining the 3D shape of the foot enables omnichannel retailing  as its solutions can be used both at home and at the physical point of sale:

Figure 2. 3D avatar feet/IBV application for mobile phones

• The 3D avatar feet/IBV application for mobile phones, available for IOS and Android, allows instantaneous 3D scanning of the foot with only three photographs (Figure 2). The images are sent to the cloud where they are processed to generate the 3D model of the foot and a set of more than 20 measurements.

• The lightweight, easy-to-use DOMEscan/IBV scanner generates a 3D digital reconstruction of the shape of the foot and calculates its measurements in just a few seconds (Figure 3).

Both technologies have been implemented by BASE PROTECTION, which has developed its own mobile application into which it has integrated the libraries of the 3D Avatar feet/IBV application. The company also has several DOMEscan/IBV devices in points of sale.

Figure 3. DOMEscan/IBV3D foot capture system

Transfer of the footwear and insole recommendation algorithms.

The user-product interaction model, developed by IBV for recommending fit and size, is configured for each company, including information on the product and the target population. As BASE PROTECTION wished to implement the size recommendation system throughout its footwear collection, it provided information on each of its product lines, as well as on the range of insoles it has developed with three different plantar anatomy designs. The procedure for the transfer was as follows:

• Extraction of the parameters of the shape of the foot. The tools developed by the IBV have made it possible to extract a set of foot parameters that summarize the key shoe fit information. For the recommendation of insoles, the indices that characterize the morphology of the plantar arch were calculated.

• Modelling of the fit. IBV adapted its parametric fit model for the company, including the entire range of BASE PROTECTION products. This model employs statistical methods that relate the shape parameters of the foot to the fit of the product.

• Configuration of the system output. The size recommendation system allows you to configure how you present the recommendation to the user. In this way, it is possible just to indicate the size recommended to the user or, for example, to provide more elaborate information such as the prediction of the type of fit expected for each size: loose, neutral, tight. The BASE PROTECTION system includes information on the recommended size for the selected shoe model and an assessment of the expected fit quality, as shown in figure 4.

Figure 4. Output of the BASE PROTECTION footwear, size and insole recommender

CONCLUSIONS

Using different technologies developed by the IBV, BASE PROTECTION has launched a mobile application, SCAN&FIT, which provides the recommended model, size and insole of the footwear that best suits each user. Using this application makes it easier for their customers to select the product that best suits their needs, ensuring the best possible fit and size without having to try on different shoe models. In addition to improving comfort and therefore worker safety, this technology also increases efficiency when it comes to the large-scale purchase of work footwear by user companies, enabling progress to be made in the purchase digitization process.

The IBV provides companies in the footwear sector with 3D foot scanning technology that can be easily integrated into their different sales channels, both physical and online, as well as fit prediction models for size recommendations that are customized for each company, using their product information and their interaction with users.

These recommendation systems can also be updated and improved autonomously using the information that users provide to the system during the purchase process.

ACKNOWLEDGEMENTS

Our thanks to BASE PROTECTION S.R.L. for placing its trust in the Institute of Biomechanics (IBV) for the development of its recommendation system.