Characterization of Prosthetic Liner Products for People with Transtibial Amputation

Abstract

Introduction Typical practitioners choose from among only two to three products when selecting liners for their patients. A lack of comparable objective information about similarities and differences among elastomeric liner products may be part of the reason. Methods Commonly used, commercially available polyurethane, silicone, and thermoplastic elastomer (TPE) liners were tested for their compressive, shear, tensile, and volumetric elasticities as well as their coefficients of friction (CoFs) and thermal conductivities. Results Polyurethane and silicone liners tended to be stiffer in compression and shear than TPE liners. Fabric backings contributed primarily to increased tensile elasticity (and thus reduced pistoning). Polyurethane liners demonstrated relatively low CoFs, whereas silicone and TPE liners had higher CoFs and wider ranges. All materials tested were essentially incompressible. Thermal conductivities of all materials were comparable and similar to that of leather. Conclusions Polyurethane liners are softer and less sticky than 16 years ago, and TPE liners have higher tensile stiffness than previously. A stiff fabric backing can increase tensile stiffness by more than 200%. Compressive stiffness may be used to characterize a liner’s ability to flow. Elastomeric liners move heat almost exclusively via conduction.

Synthesis and characterization of a silver nanoparticle-containing polymer composite with antimicrobial abilities for application in prosthetic and orthotic devices

“…The mechanical results presented in this study may not generate any inconvenience, as the values obtained were within the acceptable ranges of hardness (0 -20 on the Shore A scale) [66], density (1.0 -2.5 g/cm 3 ) [67], deformation by compression (8 -59%) [68], ultimate tensile, and rupture strength (0.030 -0.248 MPa) [69] and modulus of elasticity (0.124 -3.45 MPa) [70], for lower limb orthotic and prosthetic devices.…”

Incorporating a Ferrous Polymer Target into Elastomeric Liners for Socket Fit Sensing in Prosthesis Users

“…In development of the SEEPS polymer in our prior efforts, we noted that the polymer stiffness could be tuned to the elastomer to which it is to be attached. The tensile elasticity of the ferrous polymer was 282 kPa, within the range of commercial elastomeric liners (124–309 kPa) [ 17 , 20 ]. This match minimized shear stress at their interface when subjected to an external load and allowed the very thin layer of highly elastic fabric between them to serve as a bonding platform to keep the layers together.…”

“…The target must be incorporated into the wearer’s prosthetic liner, typically an off-the-shelf product. There are numerous liner sizes and styles; most are made of silicone, polyurethane, a thermoplastic elastomer, or a combination of these [ 16 , 17 ]. Most liners have a fabric backing on the outside to allow the liner to easily slip into a socket.…”

Synthesis and characterization of a silver nanoparticle-containing polymer composite with antimicrobial abilities for application in prosthetic and orthotic devices

“…Finally, the mechanical results presented in this study may not generate any inconvenience, as the values obtained were within the acceptable ranges of hardness (0 -20 on the Shore A scale) [64], density (1.0 -2.5 g/cm 3 ) [65], deformation by compression (8 -59 %) [66], ultimate tensile, and rupture strength (0.030 -0.248 MPa) [67] and modulus of elasticity (0.124 -3.45 MPa) [68], for lower limb orthotic and prosthetic devices.…”