Upper-Limb Prosthetic Abandonment: Functionality vs Comfort

By Marins Med (2024)

In the world of upper-limb prosthetics, abandonment rates remain a significant issue, with two primary reasons consistently rising to the surface: low functionality and discomfort. However, these two factors often stem from different parts of the prosthetic. Specifically, the socket that encompasses the residual limb is the primary source of discomfort, while the terminal device is frequently the culprit behind low functionality. Though these components must work in conjunction, they have distinct challenges that must be addressed separately. A deeper understanding of these issues could help pave the way for improved prosthetic acceptance and reduced abandonment.

Discomfort: The Role of the Socket

For many amputees, the prosthetic socket is a major source of frustration. Because the socket/arm encompasses the residual limb, the socket must provide a snug yet comfortable fit. Unfortunately, even small imperfections can lead to pressure points, skin irritation, and long-term complications like sores or infections. Additionally, a significant source of discomfort that has yet to be fully addressed is sweat buildup within the socket.

Prosthetic sockets, particularly in warmer climates or during periods of increased activity, can trap heat and moisture, leading to excessive sweating. This not only makes the socket uncomfortable but can also increase the risk of skin irritation and infection. Amputees who experience this issue may find themselves reluctant to wear their prosthetics for extended periods, further limiting the device’s usability.

The challenge is to create socket designs and materials that allow for better breathability and moisture management. Without addressing this discomfort, even the most functional terminal device may be abandoned. It's clear that socket discomfort remains a significant barrier to prosthetic acceptance.

Low Functionality: The Terminal Device Problem

While socket-related discomfort accounts for much of the physical burden of wearing a prosthetic, the terminal device is often to blame for functional dissatisfaction. For many upper-limb amputees, the terminal device is the prosthetic's "working" part—the hand replacement that must perform everyday tasks. When the terminal device is limited in functionality or difficult to use, frustration sets in.

Many of the upper-limb terminal devices currently available are outdated or overly specialized, serving a narrow range of tasks. The leading terminal device in the U.S., for example, was patented in 1912, and while it has seen incremental improvements, it is still relatively limited in terms of versatility. Amputees need terminal devices that offer both strength and precision, allowing them to handle a wide range of activities, from delicate tasks like using utensils to more demanding ones like construction work.

The ProHensor is designed to tackle this very issue. By offering a self-actuating locking system, the ProHensor allows users to securely grasp objects with ease. It’s durable enough to be used in demanding environments and can be serviced in the field, addressing both durability and practicality concerns. The functionality of the ProHook bridges the gap between traditional body-powered devices and more expensive, maintenance-heavy myoelectric options, making it a practical solution for amputees looking for reliable, versatile tools.

Additionally, the serviceability of the ProHensor enables a long-term relationship with the amputee and their prosthetist professional. Regular maintenance checks facilitated by its design allow prosthetists to make necessary adjustments and address any emerging issues, including those related to the socket's fit and comfort. This ongoing care helps prevent discomfort that could lead to abandonment, ensuring that the prosthetic continues to meet the user’s needs over time.

Two Challenges, One Goal

The industry must understand that the high abandonment rates of upper-limb prosthetics are caused by both discomfort and low functionality, stemming from different parts of the device. It’s not enough to simply focus on improving one component—both the socket and terminal device need attention. Comfortable, sweat-managing sockets and highly functional terminal devices must work together to ensure long-term acceptance.

At Marins Med, our focus with the ProHensor is on improving the functionality of the terminal device to enhance user experience. The ProHook is specifically designed with practicality in mind, empowering users to handle everyday tasks efficiently and confidently. However, we also acknowledge that broader issues related to socket comfort, especially the discomfort caused by sweat, need to be addressed in parallel. Ongoing collaboration with socket designers and prosthetists is essential for creating holistic solutions that reduce abandonment.

A Call for Holistic Innovation

If we are to reduce prosthetic abandonment rates, the industry must recognize the distinct yet intertwined nature of discomfort and functionality. Innovations in socket design must prioritize moisture management and ergonomic comfort, while terminal devices need to meet the functional demands of modern life.

The ProHensor (ProHook) is a significant step forward in addressing the functionality challenge for body-powered prosthetics. But the overall journey toward improving prosthetic acceptance isn’t complete until both comfort and functionality evolve together. By tackling these two pillars head-on, we can give more amputees the tools they need to live fuller, more active lives.