A study on skin mobility according to joint movement: Variations in mobility according to joint motion range and correlation and influence with hydrica composition

BACKGROUND: Skin structures arranged in an advantageous structure for skin stretching to facilitate movement of the human body, and have structural functions to help the movement of the joints by changing the position of the skin, such as the stretch that occurs incidentally. Proper movement of the skin is required to be efficient owing to the nature of the skin that covers the entire human body with a single connected tissue layer. AIMS: The purpose of this study was to quantify the skin mobility that occurs during joint motion and to identify the correlation and influence with hydrica composition. MATERIALS & METHODS: The subjects of this study were healthy people in their 20s–50s (20 male, 20 female), The movement of the skin marker attached to the skin was measured using X‐ray, and the hydrica composition was measured using Inbody S10. RESULTS: Experiments showed that the skin on the side at which the joint bends and wrinkles form moved away from the moving joint, while the skin on the side where the wrinkles spread out moved toward the moving joint. As the range of joint motion increases, the skin became more mobile (OR: 18.95 ± 5.91 mm, MR: 34.09 ± 7.87 mm, IR: 51.14 ± 8.73 mm, FF: 78.76 ± 12.24) (p < 0.05). As a result of regression analysis between the total amount of skin mobility and the factors of hydrica composition, it was found that the ABW (arm body water) affected skin mobility as B = 7.430 (p < 0.05, adjusted R (2) = 0.119). CONCLUSION: Based on the results of this study, it was revealed that directional movement of the skin appeared according to joint movement, and it was affected by body water.