Advances in Socket Technology: A Better Fit for Amputees

Advances in Socket Technology: A Better Fit for Amputees

A prosthesis’ socket directly interfaces with an amputees’ residual, making fit one of the most vital components of its comfort and functionality. Socket design and technology are changing with techniques and materials that take less time to make and fit. From 3D printing and optical scanning to adjustable click sockets, amputees have more choices and opportunities to live an active life.

But socket comfort and fit, no matter the design or material, start at the skin level. Before donning whatever socket you use, make sure the residual skin is clean and moisturized. If you know you’ll have an active day, consider using a liquid-to-powder product to create a friction barrier to reduce rubbing and chafing. Healthy, happy skin keeps you ready to try these new socket technologies as soon as they become available.

3D Socket Printing and Optical Scanning

3D Printer

The development of 3D printing technology, also known as additive manufacturing, can potentially change both how sockets are made and how long it takes to make them. Traditional sockets take several weeks to complete. Using optical scanning to adjust fit and 3D printers, it takes far less time to complete the socket.

The 3D printers make the sockets from polylactic acid (PLA), a lightweight but strong material used to make other body interface devices. In testing, these printed prostheses performed similarly to traditional design. However, even though the PLA sockets weigh the same as a standard carbon socket, users reported that they feel lighter. More importantly, these sockets are sturdy, secure, and comfortable.

This technology has added cost/time benefits too. Optical scans provide the measurements and visuals needed to make fit adjustments. The scans act as a virtual fitting, reducing the number of times the amputee has to come in for fittings and adjustments.

The technology still has to overcome some obstacles. For example, current research relies on machines designed to make small scale devices. However, there’s a push for collaboration between clinicians and technology developers to better tailor optical scans and 3D printers to the needs of the prosthetic industry and amputees.

Semi-Flexible Sockets

Today’s sockets  feature rigid structures and materials that withstand the forces and pressure of walking, using stairs, and running. However, these sockets require gel liners, socks, and soft materials to create a comfort barrier between the hard socket and the residual’s soft skin and tissue. These materials also help maintain a close fit, creating fit flexibility within the socket.

Semi-flexible sockets are made in different designs, but they each have portions of the socket made of flexible materials like silicone or polyurethane resins. These flexible materials redistribute shear forces, moving with the muscles yet offering the rigidity needed for day-to-day wear. The flexible portion of the socket reduces the need for socks and liners, though some may still choose to use them. These sockets also weigh less than the standard rigid design, reducing overall fatigue. 

Same-Day Socket Technology

Socket design is taking leaps forward in convenience too. Traditionally, a clinician plasters the limb, creates a mold, and fits the socket during several fittings. A socket technology called SocketMaster uses a mechanical-electric frame to optimize fit with micro-adjustments.

This fitting process allows people with limb loss to give feedback throughout the process with a technology that reduces the need for multiple visits and fittings. Instead of waiting two to five weeks for a new socket, amputees get fitted and walk out the door with their new socket within a few hours or the same day.

Adjustable Sockets

Socket comfort always comes down to fit, but the body changes over time and even throughout the day. You can gain or lose weight, gain or lose muscle mass, or temperatures may cause swelling or shrinking of the limb. Amputees may have to layer socks and liners, applying more layers or taking off layers throughout the day to maintain a comfortable fit.

Adjustable sockets let amputees adjust the fit throughout their day without taking off the socket, using dials to change the pressure in different areas of the socket. These devices are made of multiple panels, offering both targeted and overall pressure adjustments.  They’re meant for adjustment while wearing clothing, so if the residual swells from heat or walking, you can loosen the fit without taking off layers of clothing, socks, or liners.

Man sitting on exercise box with prosthetic limb.

Final Thoughts 

A comfortable socket with a good fit gives independence and mobility. As clinicians gain access to advancing technology, they’re adapting materials and techniques to the unique needs of amputees. Keep an eye out for socket innovations as they leave the test phase and enter the realm of the general public. One of them could keep you more comfortable and make it easier for you to more fully participate in the activities you love.

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