Pressure ulcers (PU) affect almost half of the patients in reanimation or geriatric units. They are localized injuries that affect the skin and underlying soft tissues, usually below a bony prominence. The main suspected causes are the excessive pressure intensity (internal tissue strains above 50 % for about 10 minutes) or prolonged compression (internal strains above 20 % for about two hours). Specific forms of PU, termed Deep Tissue Injuries (DTI), are defined as pressure-related injury to subcutaneous tissues such as skeletal muscles. DTI start in deep tissues underneath an intact skin and progress outward rapidly, causing substantial subcutaneous damages before being visible. Prevention through daily examination lacks efficiency because of the nature of DTI: when visual symptoms appear, it is often too late to prevent dramatic injuries. Measuring surface pressures is believed to be effective in alerting patients at risk against focal pressures that may cause soft tissues injury, but these measurements cannot predict dangerous internal tissue loading. It is consequently crucial to monitor soft tissues internal strains. The only way to estimate these strains from the skin surface pressures is to build a patient-specific biomechanical model of the soft tissues and the bony prominences. PU are frequent in reanimation and geriatric patients, especially at two locations: the buttocks (below the ischial tuberosities and the sacrum) and the foot (below the heel). In this study, we therefore introduce two generic models of the buttocks and of the foot that can be used as a foundation to create patient-specific biomechanical models with the objective of personalized PU prevention.