ABOVE ELBOW PROSTHESIS
Above elbow prosthesis aims to restore some of the most function from the missing arm. Researchers are working so hard to find a way of creating better above elbow prosthesis and this resolve to make it better has produced the biomechanical arm. However, the choice of which prosthesis to be used depends on the individual whether to choose a functional or a cosmetic prosthesis.
Functional prostheses could either be a body-powered or prosthesis operated through the use of a cable and harness machine that recruits the back and shoulder muscles. When the cable is pulled open the hand voluntarily opens or closes permitting a grabbing movement. There is another type which is an electric prosthesis which makes use of the electric powered indicators within a muscle contraction (EMG signals) on the residual limb and skin to supply power to the prosthesis to perform the functions of the elbow, wrist or hand. The energy is provided through a battery in the prosthesis.
The cosmetic prosthesis will not provide any function to the client however is made to appear like a real arm. This prosthesis will have an endoskeletal design. This implies that the prosthesis will be made to appear and feel like skin.
Parts of a functional above elbow prosthesis
The above elbow prosthesis will be developed from quite a few specific components. These factors enable the prosthesis to perform distinct functions. The prosthesis has to be designed to satisfactory suit the client’s need and cost.
Parts of a functional elbow include:
The suspension system major function is to stabilize the prosthesis when moving. Suspension system can be categorized as follows:
Harnessed-based system are the most used suspension system for many arm amputations. With a simple harness, known as figure-8, straps go over every shoulder and criss-cross. This suspension system has established its reliability in the course of lighter duties.
Self-suspending sockets Their foremost benefit is the ease of use. But, they do have a limited lifting potential in contrast to the harness system; decreased elbow flexion and are much less beautiful in appearance.
Suction sockets are the most used system for above elbow amputation. This device requires full contact with the stump. The skin round the stump has to be healthy and have few scarring to keep away from the wound weeping or becoming irritated.
The socket is made up of two distinct layers. There are two special designs. The first one is an inflexible internal socket that is measured and done to fit the person’s stump. A second is designed over this to appear like the other arm in colour and length.
The forearm is made up of a plastic shell. The forearm joins to the socket at one end and to the elbow mechanism at the other.
Elbow mechanisms are accessible as both body powered or externally powered devices. They usually connect to the forearm through a turntable permitting the top arm to move round.
Arm systems are generally constructed from plastic. The arm machine attaches from the elbow joint to the wrist unit. It acts to stabilize the prosthesis.
The wrist unit gives information to the region of the hand or terminal machine in space. This can be powered manually through cable or with external power. The important feature of the wrist unit is to facilitate the hand or terminal devices.