Current lower limb prostheses support ambulation by absorbing and stabilizing positions during walking. Users of lower limb prostheses rely solely on sensory information provided by the contact between the socket and the residual limb. Restoring sensory feedback could potentially improve their quality of life and participation in daily activities. Despite a high incidence of lower limb amputations, there are few studies in the literature addressing the restoration of sensory feedback in lower limb amputees, particularly studies utilizing invasive techniques. In an effort to overcome these limitations, various non-invasive methods have been tested. Despite resulting benefits such as improved gait symmetry and stability, most non-invasive stimulation systems are non-somatotopic, failing to generate a sensation referred to the patient's missing limb. From the literature, Transcutaneous Electrical Nerve Stimulation (TENS) emerges as a very promising non-invasive and somatotopically-based sensory feedback approach, capable of inducing sensations referred to the amputees' phantom limb.

Therefore, the proposed study will involve the use of TENS as a means to stimulate sensitivity and prevent perceptual disturbances associated with the interruption of peripheral nerve structures occurring in individuals undergoing amputation. These disturbances, besides influencing the development of symptoms characterized by neuropathic pain, can impact prosthesis management.

Inclusion Criteria:

1. age between 18 and 80 years;
2. unilateral transtibial amputation or transfemoral amputation at least two months prior the study;
3. stable clinical conditions;
4. skin integrity;
5. absence of cognitive deficits.

Exclusion Criteria:

1. bilateral amputation;
2. open wounds or sores on the residual limb;
3. cognitive deficits;
4. pregnancy;
5. presence of implanted medical device (e.g., cardiac defibrillators, pacemakers or infusion pumps);
6. refusal to sign the informed consent.