Quantification of Motor Compensation Following Biomechanical, Proprioceptive and Physiological Alterations Post-lower Limb Amputation.

Inclusion Criteria: * The patient must have given their free and informed consent and signed the consent form * The patient must be a member or beneficiary of a health insurance plan * Persons with unilateral transtibial or transfemoral amputees followed in the MPR department at the Nîmes University Hospital, RRL department, Grau du Roi University Rehabilitation Hospital. * All etiologies: vascular, traumatic and septic. * Adapted equipment validated by the rehabilitation doctor. * Able to walk for 5 minutes on a treadmill without technical assistance Inclusion criteria specific to healthy volunteers: * Adults (\>18 years old) and under 40 years old * Able to walk for 5 minutes on a treadmill without technical assistance. * Body mass index between 18 and 25 Exclusion Criteria: * The patient is participating in an interventional or a drug/medical device study, or is in a period of exclusion determined by a previous study * The patient unable to express consent * It is impossible to give the patient informed information * The patient is under safeguard of justice or state guardianship * Patient who has already been included in this study. * Pregnant, parturient or breastfeeding patient. * Appearance of a stump wound during the study requiring unloading. * Patient for whom the implementation of vibration stimulation is not possible Exclusion criteria for amputee patients: * Patient suffering from uncorrected or untreated visual disorders. * Patient with major cognitive disorders (MoCA \<23). * Patient with vestibular disorders or uncontrolled epilepsy. * Patient with an unhealed amputation stump. * Patient with a weight \> 135kg or \< 20kg * Patients with a FAC of 1 (i.e. patients who need firm and continuous assistance from a person to support their weight and maintain balance) or less. * Sensory impairment that makes it impossible to perceive stimulation * Significantly reduced bone density * Patient in whom it is impossible to correctly adjust the GRAIL System harness to the corresponding body part due to: * Body shape * Colostomy bags * Skin lesions that cannot be adequately protected. * Any other reason that prevents a good, painless adjustment of the harness. * Patient in whom it is impossible to correctly adjust the CON-TREX System: * Body shape * Colostomy bags * Skin lesions that cannot be adequately protected. * Any other reason that prevents a good, painless adjustment of the support systems. Exclusion criteria for healthy volunteers: * History of significant injury or surgery affecting the lower limbs (such as hip or knee replacement or knee/ankle ligament reconstruction) that could impact walking * History of neurological or psychiatric disorders that could affect locomotion or the processing of sensorimotor information. * Drug treatments affecting locomotion: drugs likely to alter walking or balance, such as sedatives, muscle relaxants or neuroleptics.