Uses of Phantom Sensations Induced by Global and Local Modifications of the Prosthetic Socket as Somatosensory Feedback During Walking in Lower Limb Amputees

Following lower-limb amputation, the loss of somatosensory information from the missing limb renders walking less automatic, more cognitively demanding, and often asymmetric, which can lead to secondary pathologies. Hypothesis: This study is based on the hypothesis that phantom limb sensations (PLS), when coherent with the prosthetic device's movements and the phases of the gait cycle, can compensate for the loss of somatosensory feedback and thereby improve locomotion for individuals with amputation. It is further hypothesized that it is possible to artificially induce these coherent and useful sensations, notably through "referred sensations" elicited by stimulation of the residual limb (e.g., via the prosthetic socket). Objectives: The project aims to: * Determine whether the natural presence of phantom limb sensations during walking impacts gait parameters. * Confirm in a larger patient population that modifications to the prosthetic socket can induce or enhance phantom sensations that are perceived as useful for walking. * Investigate whether these perceptual changes (induced or enhanced) are associated with objective, measurable improvements in gait quality.

Inclusion Criteria: * Participants with amputations: * Major lower limb amputation * Understand and be able to express oneself in the French language (for semi-structured interviews) * Affiliated with a social security scheme * Asymptomatic volunteer participants: * No major surgery on the lower limbs for at least 3 years * No minor injury to the trunk, lower or upper limbs that could influence walking for at least 1 year * Understand and be able to express oneself in the French language * Affiliated with a social security scheme Exclusion Criteria: * History of psychiatric disorders * Pregnant or breastfeeding woman * Minor * Adult subject to a legal protection measure * Person under guardianship or conservatorship * Person under a judicial protection order * Pain affecting walking (trunk, residual limb, phantom limb, contralateral limb) * Medical treatment incompatible with walking