Inclusion Criteria:  Subject with no history of chronic low back pain and with a lumbar VAS <2 for more than 3 months. Patient with chronic low back pain: pain localized between the edge of the last lower ribs and the intergluteal groove (17) for more than 3 months. Patient with a lumbar VAS > 2 for more than 3 months. Patient whose low back pain is of common origin (no underlying organic etiology). In case of lumbar-radicular pain, patient with a VAS (lumbar) > VAS (leg) Patient who speaks and understands French Patient with no history of arthrodesis or lumbar disc prosthesis Subject affiliated or beneficiary of a health insurance plan. The patient must have given their free and informed consent and signed the consent form  Exclusion Criteria:  It is impossible to give the subject informed information The patient is under safeguard of justice or state guardianship Patient pregnant, parturient or breastfeeding