Statistical Analysis Of Foot Anthropometric Data Of Young Chinese Male Population

Footwear has for long been an essential garment accessory used not only as a fashionaccessory but also as a protection mechanism that separates the human foot from the harmfulexternal world, it is considered as a basic element to be used in modern human society. It hasbeen discussed that despites the technological advancement in manufacturing techniques andmachinery, the basic elements such as comfort and fit of footwear have been widely ignored.Little advancement on footwear comfort has been made and the work done has been focusedon non-Chinese population. Ball et al.(2008) showed that apparel, footwear and in general“body-like” goods are produced based on western size standards. Then, an improvementopportunity is presented regarding this topic; meaning that further improvement is needed onfootwear comfort specially designed for Chinese population. Improvement of footwear in amass production environment is the main focus of the present work. Additionally,recommendations for improvement of footwear in a customized footwear environment willalso be outlined.An anthropometric experiment is designed and carried in which Chinese population’sfoot data is collected and stored in electronic form in order to have sufficient and reliable datasources of anthropometric information. Regarding the anthropometric study, a recentlyintroduced technology is used to acquire feet information, that is, three-dimensional scanningtechnology. By utilizing such technology the author of the present work is capable ofacquiring a comprehensive data set of foot information for each participant on theanthropometric experiment. Three-dimensional scans, foot measurements andthree-dimensional coordinates of foot landmarks information are obtained for eachexperiment participant.The availability of anthropometric information–foot anthropometric information-is thefoundation of the whole present study as later stages of the investigation require data analysisand characterization by utilizing statistical analysis and various mathematical tools. Statisticaltools offer an insight into the collected data as they unveil the underlying relationships andcharacteristics of the information. Therefore, the present study will cover the problem of shoe manufacture for Chinesepopulation from two aspects, mass production and mass customization, for mass productionpurposes a shoe sizing system is developed, proposed and relevant recommendationregarding mass customization are also outlined.The anthropometric experiment is at a first stage designed and tested on a pilot study.The formal experiment is later on carried out with a sample size of100mainland Chineseparticipants; all participants are male subjects with ages ranging from18-35years old. Foot’sthree-dimensional scans, measurements, landmarks coordinates and relevant subject’sdemographic information are collected. Both feet information is collected, resulting in a200feet three-dimensional scan database. Quality assurance methodology is applied beforehand,during and after the experiment to ensure the repeatability and reproducibility of thethree-dimensional scans and foot measurement information. All data is stored into a databasein spreadsheet format for later use and reference.The statistical analysis of the information includes basic information such as average,standard deviation, minimum and maximum values. Pearson correlation analysis along withregression analysis were carried out aiming to disclose relationships existing betweendifferent foot measurement data and also to mathematically represent such relationships.Principal components analysis (PCA) was used in the next stage aiming to minimize thenumber foot measurements needed to describe the foot shape differences. The output of thePCA shows how many foot dimension factors represent most the variance in foot’s shapeamong individuals.The next step on the study’s development was a footwear sizing system; the datarelationships and information obtained up to this stage were an input for the sizing systemdevelopment process and resulted in the creation of eight different sizing systems, each witha different value of increment between shoe sizes. Foot length and ball girth circumferenceare used to size the shoe last whereas foot length and foot width are used to size the final shoesize–the one perceived by the customer-. The relationship between ball girth circumferenceand foot width is explained by a regression equation with R=0.968. Finally, in order to address the accommodation rate of the sizing systems a probabilitydensity function (PDF) of a bivariate normal distribution (between Foot with and ball girthcircumference) is calculated showing the accommodation rate of individual sizes within eachsizing system. A comparison of the PDF with the accommodation rate of the real data sampleis carried out, results showed a difference of less than1.5%.The sizing systems contain high accommodation rate (of more than98%) with65sizesavailable but if economical considerations are pressing the development of the sizing system,the sizing system can be constrained and the number of sizes can be reduced to those withhigher PDF value. It was found that less than half of the sizes cover approximately90%ofthe population.