Upper Limb Prosthetics: Built for Comfort & Independence
Building upper limb prosthetics is both an art and a science. So while it is essential for a prosthetist to have extensive experience fitting upper limbs specifically, the care he or she takes to understand your goals, lifestyle, hobbies, and personal aesthetic is equally important. At Allcare, our goal is to get you the most comfortable, functional device based on your wants and needs, so you can get back to living your best life. And with our unique ability to build and adjust anything in-house, we can get you there faster.
At Allcare, you’re not just another patient. They care about you as a whole individual. Part of what you get for being with them is their support system within the community. I’ve not seen that anywhere else. I now have three devices from Allcare.
Filmmaker, Actress, Upper Limb Allcare Patient
The Components of an Upper Limb Prosthetic
Upper limb prosthetics are typically made up of the following components: a socket, liners, socks, and a terminal device.
A socket is the place where your residual limb will reside. The fit of the socket is critical to the comfort of your prosthesis. Every socket must be custom-designed for each patient and then adjusted as necessary for maximum comfort and functionality.
Liners are typically worn over the residual limb and then inserted into the socket. The liner can protect your skin while also helping to secure the prosthetic to your limb.
Socks are often worn over the prosthetic limb to help with fit and comfort throughout the day and over time as your limb volume changes.
A terminal device is the end piece of the prosthetic that typically falls within three categories: a hook, a hand, or a prehensor. The terminal device can be interchanged depending on the task or activity being performed. For an overview of the pros and cons of each terminal device, check out this resource from the Amputee Coalition.
Body-Powered vs. Electric-Powered Upper Limb Prosthetics
Functional upper limb prosthetics are either body-powered or electric-powered. Within the electric-powered system, you have several options of different myoelectric devices.
Working much like a brake handle on a bike, body-powered prosthetics use a harness and cable system. This system uses body movements, such as from the back or shoulders, to operate the terminal device. Body-powered prostheses are more durable and can better withstand elements like heat, water, and dirt.
These systems open and close using battery power, increasing a person’s range of motion and grip while providing more natural movements.
A myoelectric system is a type of electric-powered device that uses sensors implanted within a socket to detect remaining muscle activity, allowing arm muscle contractions to operate the terminal device.
There are currently two types of myoelectric devices:
- Traditional two-channel setup – Uses two sensors within the socket to amplify electrical impulses of the remaining flexor and extensor muscles to operate a wrist and terminal device, plus an elbow in the case of above-elbow amputees.
- Pattern recognition – Uses up to eight sensors within the socket to layer different muscle patterns in order to operate a wrist and terminal device, plus an elbow in the case of above-elbow amputees. This setup can operate various grip patterns in a more intuitive fashion. Learn more about the cutting-edge developments and advantages of recognition myoelectric devices here.
To learn more about which prosthetic, electric or body-powered, might work best for you, check out the Amputee Coalition’s overview of the advantages and disadvantages of each.
Myoelectric Powered Hands
The I-Limb Michelangelo and Bebionic myoelectric hands allow you to program custom grips and hand gestures through an app on your iPhone or Android device. These hands have individually articulating digits that enable you to grab even the most minute objects, helping you to complete tasks you could not otherwise achieve with a body-powered terminal device.
Sport-specific arms are an excellent option for people looking to take their sports or recreational activities to the next level. These are specialized upper limb prosthetics that are specifically designed to handle more intense or specific physical tasks.
The arm itself does not change based on the activity performed, but rather, it is the terminal device that is interchangeable. Once you receive your activity arm, you can choose from a catalog of hundreds of terminal devices designed for things like biking, kayaking, weight-lifting, yoga, and much more.
Transradial – Below the Elbow Prosthetics
A transradial prosthetic is for patients who have had a partial amputation of the arm, along the radial bone, that has left the elbow and some of the lower arm intact. While transradial amputations are defined by the presence of the elbow, no two amputations are alike, so it is important for a prosthetist to custom-build and perfectly adjust the prosthesis, particularly the socket, to ensure comfort and fit in the short and long term.
Transhumeral – Above the Elbow Prosthetics
A transhumeral prosthetic is for patients who have had an amputation involving the humerus, or the upper arm bone. This type of prosthetic has a few additional components, including an elbow and any missing segments of the arm below the shoulder.
Hybrid Prosthetics: Hybrid prosthetics are often a good solution for above the elbow amputees. This involves using a combination of options in one prosthetic. For example, an individual with a transhumeral amputation may have a prosthetic with a body-powered elbow and a myoelectric-controlled terminal device.
Powered Elbows: Our myoelectric-controlled elbows provide active lift allowing above-elbow amputees to power up objects off of a surface or the floor.
An amputation through a joint is called disarticulation. A shoulder disarticulation involves amputation of the entire arm from the shoulder joint, between the humerus and scapula.
This accounts for fewer than three percent of all upper limb amputations. These prostheses consist of a contoured body frame, locking shoulder joint, functional elbow, and hand. The prosthesis can be controlled by either a body-powered harness, myoelectric control, or both.
New surgical techniques, called Targeted Muscle Reinnervation, have opened many new options for patients with this amputation level. This surgery aims to reassign nerves, making it possible to control a prosthetic device by simply thinking of an intended movement.
Typical criteria for this surgery:
- Above or below the elbow or at the shoulder amputation
- Stable soft tissues
- Ability to participate in rehab
Learn more about this evolving surgical technique here.
Partial Hand or Digit Amputations
These amputations can range from a portion of one digit to the amputation of all digits through the palm. Much like other upper limb prosthetics, partial hand or digit prosthetics can be controlled by the remaining joints of the hand and wrist or by myoelectric systems.
I-Limb Digits by Ossur: I-Limb Digits allow partial hand amputees to regain the dexterity and confidence to once again perform everyday tasks. Each prosthetic finger is powered by its own motor, so patients can more easily control movement for typing, using a telephone, pointing, and more.
Naked prosthetics: Naked prosthetics design functional, high-quality finger devices that allow people with finger amputations to get back to their prior level of function.
Questions? We’re Always Here to Help.
No matter what stage of research you’re in, please contact us with any questions you have. Whether or not you choose to get a prosthetic with us, we want to be a source of information for you. Our goal is to help connect you to our community and resources, so you never have to feel you are in this alone.