Prostheses – artificial limbs

You may not even know that you have met a person with a prosthesis. The modern models are designed in such a way that they look very realistic, and they not only look good, they work like the real limbs. Thanks to the advance in technology, it has finally become possible to walk, run, swim or even climb with an artificial limb. Nowadays, the most innovative models give an arm/a hand prosthesis owner a power to control his or her fingers separately.

This invention has brought so much improvement to plenty of disabled people’s lives that it can surely be included in the group of the biggest inventions of all time. Prostheses help regain our priceless independence and feeling of normality.

Prosthesis – what is it?

In other words it is an artificial/prosthetic limb. Although our limbs are irreplaceable, prostheses are some kind of artificial replacements for them. Such a substitute is needed in many cases of either a lost limb – in many different circumstances – or an innate lack of a limb. A cosmesis is a type of prosthesis which plays an esthetic role only, usually it has no other functions. In the case of prostheses which are more functional than cosmeses, the artificial limbs consist of wires and metal rods and are supposed to be hidden by clothes.

What are the types of prostheses?

There are four main types:

  1. Below the knee – BK, transtibial – a prosthesis of a lower leg.
  2. Above the knee – AK, transfemoral – a replacement for an upper and lower leg with an
    artificial knee.
  3. Below the elbow – BE, transradial – a prosthesis of a forearm.
  4. Above the elbow – AE, transhumeral – a prosthesis of an upper and lower arm with an elbow.

How do the artificial limbs work?

A prosthesis is build of a few elements –the limb, the socket, the attachment mechanism and the control system.

The limb is usually made from carbon fiber (strong and light material) and covered with foam or plastic in the colour of body. The weight of a prosthesis plays a crucial role for a user. Actually, our natural limbs weight quite a lot and it would be too hard to move with the artificial ones in the same weight.

When it comes to the socket, it is a very important part deciding about the comfort of using the prosthesis and the effectiveness of its work. It is a connecting part for the artificial and the remaining natural part of a limb – residual limb. It must be made by a professional prosthetist, well fitted and then, adjusted regularly.

The appropriate attachment mechanism is necessary to support the connection between the prosthesis and the residual limb. It can be in a form of an elastic sleeve, a suction socket, straps or harness.

The control system is a substitute for the natural brain-muscles cooperation. In the simplest prostheses the role of muscles is played by a system of cables, the artificial legs usually use just the gravity to work. More sophisticated prostheses are controlled by electric mechanisms. For example, in myoelectric the complicated system of electrodes and electric motors help control the artificial limbs similarly to the natural ones.

The good cooperation between a patient and a prosthetist is fundamental to successful work of a prosthesis. And generally, the process of getting accustomed to the new part of your body must take some time and trouble, yet it is well worth the effort.