Levels Of Upper Extremity Amputations
- Shoulder Disarticulation
- Transhumeral (AE)
- Elbow Disarticulation
- Transradial (BE)
- Wrist Disarticulation
- Partial Hand
Prosthetic Design Options For Upper Extremity Amputations
PassiveThis type of prosthesis can be used for all levels of amputation. It is used primarily to replace the body part that is missing. This promotes a healthy body image, and is also functional in that it can assist the sound side arm in activities such as holding or placing objects.
Mechanical (Body Powered) This prosthesis uses body movements to operate the terminal device (hand or hook.) The prosthesis is connected to the body through the use of cables and harness. Using movements of the shoulders and the arms, the person can open and close the terminal device.
Myoelectric (Externally powered) The Myoelectric uses signals from muscles of the residual limb to control the opening and closing of the terminal device (hook or hand) or elbow depending on the level of amputation. Electrodes are incorporated into the prosthetic socket and by contracting the muscles of the residual limb, electrical signals are sent to the motors which open and close the terminal device (hook or hand) or lift and lower the forearm at the elbow.
Socket-The socket is the part of the prosthesis which is contact with the residual limb. It allows the various components to be mounted to the prosthesis including harnessing, elbows, wrists, terminal devices, etc.
Harness – A harness holds the device to the body so the prosthesis can be used properly. When using a body powered prosthesis, the harness is used to open or close the the terminal device. Depending on the level of amputation it may also be used to lock and unlock an elbow. The harness can be worn over an undershirt to help minimize the friction between the harness and the skin. This will also help keep the harness clean.
Elbow – This part of the prosthesis allows extension and flexion of the forearm. Body powered elbows are flexed using a cable connected to the harness or by lifting and locking them with the sound limb. Electronic elbows are also available for use with myoelectric prosthetics which uses bionic technology to function.
Wrists – There are many types of wrist units that offer the user the ability to rotate his or her terminal device to any position, offer a quick disconnect of the terminal device to easily change between a hook or hand or any other type of terminal device, and also units that allow for flexion and extension of the terminal device at the wrist.
Terminal Devices – There are three main types of terminal devices for the upper limb prosthesis: hands, hooks and specialized terminal devices.
Hands – Hands can be either passive (non-functional) or functional. Functional hands can be either body powered or myoelectric.
Hooks – Hooks are used instead of traditional hands. They allow easier manipulation of objects.
Specialized terminal devices – Specialized terminal devices are customized for a sport, hobby, or profession. You could have a baseball mitt attached to the wrist or a pool/snooker rest.
Patient’s limb When your physician has given clearance to begin the prosthetic fitting process, your prosthetist will take a plaster cast of the limb which will provide him/her with a model to make the prosthesis. Prior to this appointment, your prosthetist will have assessed your individual needs and goals for life as an amputee. This information is extremely important when determining which type of prosthetic device will be most suitable for your individual needs. These factors include the length and condition of your residual limb, range of motion and strength, your activity level, occupation or leisure activities, and current health status.
Occupation The type of one’s occupation is also considered when developing a prosthetic device. Whether it is a light duty or heavy duty type of employment, our practitioners fit each patient specifically to suit their needs.
Leisure Activities Our ultimate goal at Comprehensive Prosthetics and Orthotics is to restore mobility and quality of life for each patient and help the individual return to an active lifestyle which includes previous hobbies, sports, and recreational activities. Prosthetic components today offer the amputee a variety of options that may help make participation in recreational activities possible. Be sure to express your goals to your prosthetist so that the most appropriate components can be selected for your prosthesis.