special subjects
Limb Prostheses Options
Upper Limb Prostheses
The hand has psychosocial significance. Amputation can affect a person's self-perception and/or identity and impact relationships and career. Psychologic counseling can help a person cope. The human hand is complex. Often two different prostheses are needed to provide optimal function for general daily activities and for specific activities. There are 5 general types of upper limb prostheses: Passive prostheses Body-powered prostheses Externally powered myoelectric prostheses Hybrid prostheses Activity-specific prostheses Passive prosthesesassist in balance, stabilization of objects (such as holding down paper when writing), and recreational/vocational activities. They look like a natural limb and are the lightest and cheapest, but they do not provide active hand and joint movement. Body-powered prosthesesare the most common, because they tend to be less expensive, more durable, and require less maintenance. A strap-cable system holds the prosthesis on and uses the motion of the person's shoulder blade and upper arm to operate the hook, hand, and/or elbow joint. Some systems use the opposite arm to trigger one particular function; one end of a strap encircles the opposite arm at the armpit, and the other end connects to a cable that controls the terminal device (hook, hand, or specialty device for particular function). People involved in physical labor typically favor this type. Externally powered myoelectric prosthesesprovide active hand and joint movement without needing shoulder or body motion. Sensors and other inputs use muscle movement of the residual limb or upper body control electrically powered actuators that provide greater grasp force than body-powered prostheses. Hybrid prosthesesare typically used for higher level upper-limb amputations. They combine specific features of body power and myoelectric power. For example, a body-powered elbow might be combined with an externally powered hand or terminal device. Activity-specific prosthesesare for people who participate in activities that could damage the residual limb or everyday prosthesis, or when the everyday prosthesis would not function effectively. These prostheses often include a specialty design interface, socket, suspension system, and terminal device. Activity-specific terminal devices can allow the person to grasp a hammer and other tools, a golf club, or baseball bat, or hold a baseball glove. Others aid in various specific activities (for example, swimming or fishing). These prostheses can be passive or controlled by the amputee. 