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.