Transtibial Amputation

Transtibial amputation significantly impacts patient autonomy and quality of life, primarily due to the limitations of conventional rigid sockets, which restrict comfort and joint range of motion. The Access Socket (AS) is an innovative prosthetic socket combining a rigid carbon-fiber structure in key load-bearing areas with flexible urethane-resin (ProtheFLEX®) zones in regions typically rigid in conventional sockets. This hybrid design aims to improve comfort and pressure distribution while preserving the mechanical properties required for ambulation. The AS has already demonstrated benefits in transfemoral amputees and is now reimbursed in France for that population. A preliminary uncontrolled study in 12 transtibial amputees suggested significant improvements in perceived function, comfort, satisfaction, and mobility. This multicenter, randomized, open-label, two-arm crossover study aims to compare the (AS) with the standard rigid socket (RS) in 25 adults with transtibial amputation. Participants will wear each socket for approximately 4 weeks (after a 1-2 week adaptation period) in a randomized order. The primary outcome is the Patient Specific Functional Scale (PSFS). Secondary outcomes include comfort (SCS), satisfaction (OPUS), psychosocial adjustment (TAPES-R), mobility (PLUS-M), prosthesis utility (PEQ-U), and the proportion of patients electing to keep the AS at study completion.

The investigators do not yet know how a prosthetic socket with adjustable panels affects the performance of people with a lower limb amputation compared to a conventional prosthetic socket. The primary objective of this study is to compare an adjustable and conventional prosthetic socket and use this information to determine the optimal socket that would improve rehabilitation and function in people with lower limb amputation.

The population of older Veterans with non-traumatic lower limb amputation is growing. Following lower limb amputation, asymmetrical movements persist during walking and likely contribute to disabling sequelae including secondary pain conditions, poor gait efficiency, impaired physical function, and compromised skin integrity of the residual limb. This study seeks to address chronic gait asymmetry by evaluating the efficacy of two error-manipulation gait training programs to improve gait symmetry for Veterans with non-traumatic lower limb amputation. Additional this study will evaluate the potential of error-manipulation training programs to improve secondary measures of disability and residual limb skin health. Ultimately, this study aims to improve conventional prosthetic rehabilitation for Veterans with non-traumatic amputation through gait training programs based in motor learning principles, resulting in improved gait symmetry and lower incidence of long-term disability after non-traumatic lower limb amputation.

The goal of this clinical trial is to 1) demonstrate the feasibility of monitoring pressure, temperature, and lactic acid density of sweat inside the prosthetic socket, and 2) verify the relationship between mechanical pressure and Lactic acid density of sweat for lower limb amputees among transtibial amputees. The main questions it aims to answer are: * Is it feasible to reliably monitor pressure, temperature, and lactic acid density inside the prosthetic sockets simultaneously? * Will the lactic acid density increase with higher pressure exposure? The participants are expected to wear the newly developed E-SWEAT system on their residual limb and are exposed to two activities, walk which generate mechanical load on the residual limb, and a yoga post - birddog, which does not generate mechanical loading on the residual limb. The E-SWEAT will measure pressure, temperature, and lactic acid density of sweat during these tasks.

The investigation is an early feasibility study in up to 5 subjects, in which the primary objective is to capture preliminary safety and effectiveness information on the Magnetic Bead Tracking system.