Clinical Research Directory

Participants with unilateral amputations and a control group will undergo a comprehensive walking analysis. In a lab setting (on a treadmill or floor), their gait will be recorded using inertial sensors, EMG, force plates, and motion capture, while an EEG cap and a NASA-TLX questionnaire will assess cognitive load. Capable participants will also perform a walking test on a real-world outdoor course with varied terrain. The data will be analyzed to compare walking patterns between groups (amputees vs. controls, and amputees with vs. without phantom limbs). Finally, participants will describe any interactions they perceived between their phantom sensations and walking during the tests.

Participants reporting referred sensations in gait analysis phase will undergo further testing. The study will investigate whether prosthesis pressure or a specific socket interaction causes these sensations. A 3x3 cm grid will be drawn on the residual limb to systematically map referred sensations using various stimuli (brush, pressure tip, electrical stimulation). Participants will rate the intensity and describe the location of any resulting phantom sensations. This mapping will be repeated after 6 months to assess the stability of these sensations over time, with the ultimate goal of potentially using them to provide sensory feedback for prosthesis users. The session will last approximately 2 hours.

In 10 unilateral transfemoral amputees with stable induced phantom sensations, this phase evaluates how a personalized socket modification affects phantom sensations and walking. With the prosthetist, a localized thickness (e.g., silicone insert) is added inside the usual socket at the stable stimulation sites identified on the residual-limb map, after measuring socket pressure with a thin sensor array. Each participant is tested in two conditions in a fixed order: usual socket first, then modified socket. The order is not randomized because induced sensations may persist after the modification is removed. For each condition, gait is analyzed in the laboratory and on the ecological course (4 sessions; conditions no more than 4 weeks apart). Participants describe their sensations, rate cognitive load, effort and socket comfort, and indicate which condition is most helpful for walking.

A semi-structured interview will be conducted to ask participants to describe their phantom limb sensations (type, location, intensity) under three conditions: without their prosthesis, while standing with it, and while walking with it. This aims to identify factors influencing these sensations. Additionally, a brief physical examination of the residual limb will be performed to see if touch in specific areas triggers any referred sensations.