Arm amputees have to decide between a mechanical prosthesis and an electric one for active function. There are advantages and disadvantages to using a mechanical prosthesis, and to using an electric prosthesis. An amputee must be aware of these in order to make an informed decision about the type of limb that will meet their requirements for function and appearance.

For higher levels of amputations, such as the above-elbow or shoulder disarticulation amputee, a combination of mechanical and electric functions, called a "hybrid" design, is often recommended. An above-elbow amputee may have a good enough range of motion and upper body strength to operate a mechanical elbow without difficulty, but may still benefit from an electric terminal device, whether a powered hook or hand. For example, a prosthesis might include a myoelectric hand, a mechanical cable-operated elbow, a switch controlled electric wrist and a passive mechanical friction humeral rotation unit.

Among the advantages of a mechanical prosthesis is the freedom to use the limb in most physical environments (such as dirt, water and grease) and the ability to achieve a high level of accuracy and speed. Fine manual dexterity, comparable to a pair of tweezers, and durability, due to its simple design, are also among the advantages. The primary disadvantages are the discomfort caused by the shoulder harness (it can be uncomfortable and rub where the harness contacts the skin) and the unappealing (to some) cosmetic appearance of the standard hook (there are also mechanical hands that offer a more natural appearance). The advantages and disadvantages are the opposite of those for the electric prosthesis.

The advantages and disadvantages of an electric prosthesis are the opposite of those for the mechanical prosthesis. The primary advantages of the electric prosthesis are the comfort provided because of the suspension method - usually a self-suspending socket is used instead of a harness. The electric prosthesis also has a higher level of pinch force, up to five times greater than a cable-operated hand, without requiring more effort by the amputee. Disadvantages of the electric prosthesis include the inability to use it in environments where dirt, water, dust, grease or solvents are present because these elements would damage the prosthesis. Although the grip force of the electric prosthesis is stronger, the operation may be slower than that of a mechanical prosthesis.