Development of a finite element-based model for the thermal assessment of transtibial prosthetic liners.

BACKGROUND

Thermal discomfort because of elevated residual limb skin temperatures and/or perspiration within the prosthetic socket is frequently reported among people with amputation.

OBJECTIVE

To evaluate the impact of the thermal conductivity characteristics of prosthetic liners on transtibial prosthesis heat dissipation, following postactivity rest.

STUDY DESIGN

Time-dependent heat transfer study in solids using finite element analysis.

METHODS

A three-dimensional model of the transtibial residual limb was developed by simplifying the geometry to tapered, layered cylinders. Four prosthetic socket liners of varying thermal conductivities were then added to the exterior, and the final surface temperatures of the skin layer were analyzed.

RESULTS

Warmer temperatures were observed near regions with greater muscle volume; cooler temperatures were observed at the distal end of the simplified model. The final residual limb skin temperatures for each prosthetic liner were found to be significantly different from one another. Overall, the average final surface temperatures of the skin layer at the end of postactivity rest was 3.85°C ± 0.12°C greater than the initial surface temperatures of skin layer.

CONCLUSIONS

None of the prosthetic liners made a significant reduction in residual limb skin temperatures after activity. The results indicate that the focus should be on other material properties of the prosthetic liners or active cooling systems.