The various types of arm prostheses

If you are about to undergo – or have undergone – an arm amputation, you probably want to learn more about the best possible prosthesis for your situation. But there are so many options to choose from! The type of prosthetic arm that is best for you depends on a number of factors. Here we explain more about the different types of prostheses that are available.

In choosing a prosthesis, it is important to first determine what is important for you personally. To what extent, for example, do you want your hand to function in a particular way? The system that is used for functioning affects this. There are four different types:

• Cosmetic: a prosthesis that only serves a support and aesthetic function.
• Mechanical: controlled using a cable system. The user operates it with torso movements.
• Myoelectric: the prosthesis is controlled by muscle signals.
• Hybrid: a combination of mechanical and myoelectric.

To use these prostheses in the right way requires training and practice. This takes place with a multidisciplinary team comprising a rehab specialist, an occupational and physical therapist and an orthopaedic consultant. They will help you use your (new) prosthesis as effectively as possible.

The control system of a prosthesis is not the only consideration when choosing a prosthesis. The amputation level of your arm is equally as important. We also explain the different prostheses for each amputation level.

Is part of your hand or only a few fingers amputated? There is a prosthesis that contains a few, several or parts of a finger. With this type of prosthesis, you can choose between a silicone model or one in which you can move the individual fingers (in full or in part). This lets you optimise the grip function of all or part of the fingers. For these prostheses, you consult with a special "hands team" that includes an occupational therapist. The team trains you in the general everyday use of the prosthesis.

Have you undergone a wrist amputation, also called a wrist disarticulation? In this case, you are usually given a prosthetic socket onto which the prosthetic hand is attached. This provides added stability and functionality. The downside? The forearm may be longer than the "healthy" side, but there are more and more systems available that limit this to a minimum. A partial hand prosthesis or silicone fingers can offer a practical solution.

All types of amputations between the wrist and elbow actually fall into the category of forearm amputation. With a prosthesis on this amputation level, you need a hand that can imitate the grip function of your hand. If you want, you can also opt for a wrist rotator, so that you lose virtually none of the functionality of your arm. For this reason, myoelectric prostheses are usually chosen for forearm amputations. Multiarticular hands are also becoming more advanced, with not only two fingers that you can move, but also the thumbs and every finger group separately. This gives you much more grip and stability with your prosthetic hand.

But that’s not all. Developments in forearm prostheses are taking place rapidly. These developments are focused on as natural control of the various components as possible, such as intuitively or thought-controlled.

Was your arm amputated at the elbow joint, also called elbow disarticulation? If so, you can opt for a hybrid system. In this case, the elbow is secured with a cable, while the hand and wrist are controlled by a myoelectric system.

With an upper arm amputation, most people choose a prosthesis that is fully controlled by a myoelectric system. This offers more freedom of movement because few to no bandages are needed to control the elbow or hand. With this prosthesis, you are free to choose the various components. What’s important to you? The possibilities include an electric elbow, a wrist rotator and a multiarticular hand. This prosthesis is quite complex, which means you need the right type of training to learn to use it as effectively as possible.

After this type of amputation, you not only lose the wrist and elbow joint, but also part of the shoulder joint. So, in determining the right prosthesis, it is important to choose one that can imitate the shoulder joint – both in its fore and aft movement. These components can be controlled with myo-signals. These signals are located together with an orthopaedic consultant to make sure you choose the right components. The prosthesis is attached using a shoulder cap.

The possibilities are virtually endless – depending on your amputation level and preferences. What did you consider when choosing your prosthesis? Or, if you are facing a choice, what kinds of considerations should you make? Share your tips and help each other!