[en] Mammary reconstruction following mastectomy involves breast augmentation, which probably sets the skin under tension. This aspect of mechanobiology has rarely been explored in an objective way. The aim of the present study was to mesure the biomechanical properties of skin using a suction method. Eight sites of the thorax were assessed in 26 cases of mastectomy performed in 20 women aged 49+/-7 years. In order to distinguish the effects of breast augmentation from forces exerted by earth gravitation, measurements were performed in standing and lying down positions, both before and after breast augmentation of about 450ml.