A Primer on Breathable Prosthetic Liners
Sweating profusely underneath your prosthetic liner isn't limited to rock climbers and marathon runners. Heat and moisture buildup plagues every prosthetic user every day. And if you wear a prosthetic liner, then you know that sweat magnifies a lot of prosthetic-related issues.
Inside your prosthesis, sweat acts as a lubricant and introduces unwanted movement between your residual limb and the socket walls. This extra movement, regardless of how minor, can cause chafing, reduced suspension, premature prosthetic liner wear, and poor walking patterns.
Why do prosthetic users sweat so much?
When you become hot, you sweat; your body uses perspiration to regulate its temperature. As a prosthetic user, you tend to use more energy, generating more heat and requiring the body to sweat even more to cool down.
This fact of life is compounded for prosthetic users because their "radiator" or skin surface area is reduced. To make matters worse, prosthetic liners and socket technologies act as insulators trapping moisture and negating nature's ability to regulate its body temperature.
"Trans-tibial amputees expend 20-40% more effort to walk, but at the same time, their body surface area is typically reduced by 10-15% which impacts cooling capacity.*"
*Seymour, R. Prosthetics and Orthotics: Lower Limb and Spinal. Philadelphia: Lippincott, Williams and Wilkins 2002. By Douglas C. Smith, MD, ACA Medical Director
Treatment Options for Amputees
Today, prosthetic users have a myriad of options available to manage excessive sweating. These options include prosthetic antiperspirant, electrical stimulation, botulinum toxin, and surgery.
Modern-day options do offer some success in reducing or mitigating excessive sweating, however many of these treatments don't address one of the leading causes of excessive sweating—reduced body surface area for cooling.
Today's Socket Technology
Vacuum suspension is widely considered by many as cutting-edge socket technology for suspension with an added benefit of reduced perspiration. Vacuum technology works through expelling air from between your prosthetic liner and socket through a one-way valve embedded in your socket. However, what expels trapped air and moisture between you and your liner? Gel and silicone liner materials are impermeable and allow moisture to build up and act as a lubricant.
Hello, Breathable Liners
The introduction of breathable liners allows prosthetic users to take one step closer to manage and solve issues related to excessive sweating. To date, two manufacturers—Endolite and Uniprox—have taken what was once an impermeable barrier and created a new generation of prosthetic liners that allow prosthetic users to sweat through.
Uniprox SoftSkin Air
Uniprox, the company behind the Softskin Air prosthetic liner has reengineered silicone to mimic sweat pores. The Softskin Air's silicone structure contains micropores that allow sweat and moisture to flow through the liner, keeping the user's residual limb significantly dryer and prosthesis more secure.
Endolite Silcare Breathe Liners
Endolite has taken a different approach to help prosthetic users overcome excessive sweating. Their Silcare Breathe Liners feature laser-drilled perforations along the length and bottom end to allow moisture to escape. Endolite's breathable technology uniformly disperses these specially shaped holes allowing moisture and air to escape and providing a dryer environment as well as improved prosthetic suspension.
Artemus Labs
A new breathable liner is on the horizon. It promises to proactively cool your residual limb before it begins to sweat. Artemus Labs claims their technology can preemptively limit sweating through an innovative structural design that incorporates elastic polymers.
Currently, their breathable prosthetic liner is in the design and testing phase without a release date.
In Summary
Breathable liner technology works by taking advantage of the natural forces within your prosthetic socket as you walk. These forces are created when your residual limb presses against the socket and expels trapped air and moisture through "man-made sweat pores" within a breathable prosthetic liner. Combine this liner "breathability" with advanced sweat-wicking sock technology, and this summer may become significantly more tolerable.
