Abstract:

Objective Human morphology characterization and quantification play an important role in garment fit, pattern generation and body type classification. The characterization and differential analysis of human morphology under the same number of sizes deserves to be explored in depth. To characterize the morphological differences in body surface shapes under the same size category, this study is focused on the shoulder, chest, and waist horizontal-sections related to the prototype pattern.

Method The three-dimensional point cloud data of 145 young women aged 18-25 years were obtained through [TC]². Samples with the highest proportion of size 160/84 A were selected. K-means clustering was used to quantify the morphological characterization after subdividing the body types that accounted for the largest proportion of the body type, extracting the horizontal circumference cross-section curves of the shoulder, upper bust, bust, under bust, and waist of each classified intermediate body. Due to minor movements or variations in standing posture during 3-D scanning, coordinate system discrepancies may be appeared between the characteristic cross-sections and the system coordinate system. To address this problem, the smallest external rectangle method was applied to align the x and y axes of the characteristic cross-sections in the system coordinate system. Then, each horizontal cross-section was aligned with the mass center as the origin. Subsequently, the cross-section polar diameters based on each body shape morphology were used to plot the centroid-curve for morphological quantification and analysis.

Results The body type of 160/84 A was divided into round-thick body, wide-flat body and medium body, accounting for 7.69%, 53.85% and 38.64%, respectively. The average chest circumference and waist circumference of three types of 160/84A sub-body types were (83.70±0.56) cm and (66.84±5.57) cm, respectively. The shoulder width of the three sub-body types was found to follow the order of wide-flat body > medium body > round-thick body, with a maximum range of 3.82 cm at the shoulder point. The round-thick body has the thickest upper bust circumference, bust circumference, and under bust circumference, followed by the medium body, while the wide-flat body has the thinnest bust circumference, with maximum ranges at the front center of 3.22 cm, 3.62 cm, and 2.97 cm, respectively. The shoulder position of the wide-flat body was 10° away from the anterior-middle direction than that of the round-thick body and medium body, and the chest position of the wide-flat body and medium body was 10°-20° away from the lateral suture direction than that of the round-thick body.

Conclusion The results showed that although the data of height and chest circumference of the same national standard model were similar, there were morphological differences. For the wide-flat body type, the most notable differences occur at the shoulder point and where the cross-section intersects with the lateral suture. In contrast, the round-thick body type shows significant differences at the intersections of the cross-section with the anterior and posterior midpoints. Then, each cross-section was analyzed, revealing that shoulder morphology shows the greatest variation at the shoulder peak. Additionally, the upper bust circumference, bust circumference, and under bust circumference display the most significant differences at the anterior midpoints. Girth morphology differences are most pronounced at the lateral midpoints for each body type.

Key words: shoulder-chest-waist, characteristic cross section, K-means clustering, polar radius of section, human body morphology representation, young women