An analysis of the negative asymmetry in the coronal body shape of the old people in South Korea

Abstract Background Existing positive shape models are based on values for the right side of the body. To the best of our knowledge, this is the first comparative study to analyze both left- and right-side data to explore asymmetrical body characteristics, considering that most older people are not able to maintain a healthy spinal vertical tilt presentation. In this study, 3D scanning and 3D measurement were used to analyze and study the asymmetry of the elderly in South Korea to provide more complete basic size data for the development of clothing patterns for the elderly.Methods The calculated values were analyzed by ANOVA and correlation analysis, and the paired sample t-test was performed to find asymmetrical characteristics of the older adult body. Finally, we used the independent t-test to analyze sex differences. Geomagic Design X software was used to record the coordinates of the measured points to reconstruct 3D models of the older adult body. We present a new method based on analysis of the vertex-anterior neck plane, the anterior neck-omphalion plane, and the omphalion-crotch point plane as benchmarks for the center of the head, the upper torso and the lower torso, respectively, to determine lateral asymmetry.Results The Kolmogorov-Smirnov normality test indicated the tendency of the torso to tilt to the right in older men and women. Compared with the inclination of the head, the inclination of the lower torso is more obvious. The correlation analysis results show that the tilt of the head does not affect the asymmetrical characteristics of the trunk.Conclusions This study did not use the traditional median sagittal plane as a central datum plane, instead separating the model according to the structure of the human body into the head, upper body, and lower body, with three independent central datum planes. Therefore, this study contributes an analysis of human asymmetry, thus providing more complete basic size data for the development of clothing patterns for the elderly in South Korea.