Stage 3: Choosing an Artificial Limb(s)

Artificial limbs have come a long way from the early wooden and aluminum versions used after the First and Second World Wars. New technology is making artificial limbs more cosmetically appealing and functional. Artificial legs are very useful for providing mobility and stability, and artificial arms can help with many daily household actiivities. There are many specific types of prostheses, including special limbs or devices for certain tasks and activities so it is very important to discuss your expectations and requirements with the prosthetist.

To make the best use of the time during your appointments with the prosthetist, it is a good idea to write down any questions you think of in advance. You do not want to forget anything. Taking notes during these meetings that you can refer back to later is also helpful – with so much information coming your way these notes can be reviewed when you have more time.

If you are an arm amputee, your choices range from a passive to a more functional prosthesis. Passive arms have no grasping function but have a good cosmetic appearance. Functional arms can either be body-powered or electric (most often myoelectric). Cable-operated hands and hooks are known as “body-powered” prostheses and are operated by means of a cable and harness system. By using the back and shoulder muscles, the cable is pulled which either opens (“voluntary opening”) or closes (“voluntary closing”) the hand.

A “myoelectric” prosthesis is operated when the electrodes pick up muscle (Greek: myo) impulses from your residual limb. These are then translated into electrical signals that are sent to the electric hand to open or close it. The power is provided by a battery in the prosthesis. Although less common than myoelectric arms, there are also electric arms that are operated by other means, like a switch that you can turn on and off. Some types of arms have the option of either being myoelectrically controlled or switch-controlled.

If you are a leg amputee, you will be fitted with one of two types of limbs. An exoskeletal prosthesis has a hard outer shell made primarily of plastics and laminates. An endoskeletal, or modular prosthesis, has the tube or pylon frame that acts as a type of “skeleton.” A soft foam cover is usually applied over the prosthesis, which is shaped to match the sound limb.

There are many pros and cons for different types of artificial limbs and with your prosthetist you will discuss which characteristics are the most important for you. Some of the considerations are:

• Your level of activity Artificial limbs are designed for low, medium and high-level activities. Usually low-activity limbs are simpler in design and may be lighter in weight than high-activity ones, which may contain more complex components. Endoskeletal components are lightweight, require few adjustments, and have parts that are easily interchanged. Exoskeletal components are durable, last longer and can endure strenuous wear.
• Your health Amputees with an active lifestyle may require limbs with more advanced function (though there might be extra maintenance involved). Sometimes less active amputees, and those who have conditions like diabetes and vascular disease, choose to use simple artificial limbs that are comfortable, easy to use and/or expend less energy. For example, a “slide-on socket” which is easy to slip on with a lightweight activity belt could be useful if you are a senior amputee. Stance control safety knees are useful for leg amputees with limited muscle control since they contain a weight-activated safety brake.
• Your level of amputation(s) Leg amputees will need to consider the type of foot that is suitable for them. For instance, a partial foot amputee can use a shoe filler for better function. Some leg amputees will consider an articulated ankle (with jointed parts that move) and an above-knee amputee will also consider the type of knee joint they require.Similarly, partial hand amputees might be interested in an opposition post (a device that allows partial hand amputees to grasp while retaining sensation). Arm amputees will consider the type of terminal device they will use for hand function as well as possibly a wrist joint. Above-elbow amputees will also consider the type of elbow joint. Hybrid fittings that incorporate at least two different features – such as a body-powered and myoelectric hybrid arm combining an electric hand and a cable-operated elbow – are common in above-elbow fittings.The weight of each component becomes an important consideration for high-level amputees. Most bilateral and multiple amputees can be fitted with (an) artificial limb(s), but sometimes other mobility aids like a wheelchair are more suitable. Some amputees who use prostheses for certain activities rely on their wheelchair for activities involving long distances.
• Cosmetic look versus functionality There is sometimes a trade-off between the cosmetic look (cosmesis) of an artificial limb and its function. If you are a leg amputee, for example, highly cosmetic coverings are expensive and may be easily damaged if you lead a very active lifestyle. If you are an arm amputee, hooks are very functional because of their good pinch and grasp function, but do not look as natural as a passive or myoelectric hand. You have to find the right balance of cosmesis and function to suit your needs.
• Other options In addition to the standard limb, you may consider whether you need additional specialized limbs. Many amputees have different artificial limbs for specific activities. A prosthetist can make a recreational arm or leg specially designed for sports, such as skiing or swimming. Specific devices, like a simple ring attached to the handlebars of a bicycle for upper-limb amputees, can also be made. Remember, the prosthetist is an expert on artificial limbs, but you are an expert on yourself and what you need!

This section has been created using information provided by War Amps, minor amendments have been made, which reflect more accurately the UK rehabilitation process.