Biomechanical Properties of the Skin on the Dorsal Trunk in Young Men

The skin is composed of high molecular weight fibers such as collagen and hyaluronic acid and has a barrier function against mechanical stimulation. On the other hand, the elasticity and viscoelasticity of the skin are essential functional factors in the relationship between skin and body movements. Of the main components of the skin, collagen is involved in shape maintenance and elastin is involved in elasticity. The skinʼs biomechanical properties differ from site to site due to the content of these components and the arrangement of fibers. The trunk is the largest in the human body, and the trunkʼs skin affects not only inherent trunk movements but also limb movements. In this study, the skin on the dorsal trunk is divided in detail and the biomechanical properties of each site are compared and examined. Fifteen healthy young men (21.9 ± 0.4 years) participated in the study. The measurement zone was divided into 5 equal parts from the upper end to the lower end, 4 equal parts between the left end and right ends, and 20 (4 × 5) blocks in total. The measurements of skin biomechanical properties were conducted by using the help of CutometerⓇ MPA 580. The results of this study express a specific distribution of elasticity and viscoelasticity in the skin on the dorsal trunk. Regarding the biomechanical properties of the dorsal trunk, viscoelasticity was significantly lower on the caudal side than on the cranial side and significantly lower on the lateral side than the medial side. There was a tendency for the elasticity to be significantly higher on the lateral sides than the medial side. The findings of this study suggest the relationship between the biomechanical properties of the skin of the dorsal trunk and the movements of the limb as well as trunk movements.