The aim of this study is to assess the intra and inter-subjects variability of the pressure measurement cartography in healthy and well and able volunteers, sitting on a rigid base during two hours.

• The purpose of this study is to understand the formation of pressure sore, to improve the care of paraplegic patients.
• This pilot study is going to help to establish a model in healthy volunteers in the prevention of pressure sores.

Inclusion Criteria:

• more or equal than 18 years old
• age between 20 and 30 years old
• affiliation to social security or similarly regime

Exclusion Criteria:

• Person with pacemaker
• Person with a history of lumbar pain, chest or/and cervical pain.
• Person with an history of lumbar, chest or/and cervical muscular disorders,
• Person with history of circulatory problems,
• Person with history of skin pathologies at the seat area,
• Protected person referred to in Articles L1121-5 to L1121-8 of the Code of Public Health
• Person having a total annual compensation for the participation in biomedical research higher than €4460.