A finite element analysis of gravity effects on breast based on microgravity geometry

Abstract

Breast is a soft organ and it becomes more deformable and droopier along aging. It is caused not only by the internal factor such as mammary gland ratio, but also by the external factors, such as gravity and vibration. Brassiere plays an important role for supporting and shaping breast. To optimize brassiere design, this study aims at investigating the gravity effects on breast in three postures of daily life: sitting, supine, and forward bending postures. A finite element model was constructed based on the three-dimensional geometry in the neutral position which was scanned in microgravity environment by aircraft parabolic flight. Mechanical properties of different soft tissues were estimated by approximating the deformed shape in a sitting posture under gravity. They were further validated through simulations of supine and forward bending postures under gravity. The proposed model can be used to predict the stress distribution in breast under gravity.