Prosthetic principles in bilateral shoulder disarticulation or bilateral amelia ∗

Following a brief survey of the historic development of pneumatic prostheses the actual principles of prosthetic management in bilateral shoulder disarticulation or bilateral amelia are explained.

The active functions are restricted to active pronation and supination, active gripping of the terminal device “hook” or “hand”, combined with pneumatic locking of free swinging shoulder and elbow joints in one artificial arm; the cosmetic arm provides only space for the power package in the resin socket of the upper arm. Both arms are suspended on a Simpson frame.

Thus optical control is concentrated on the movements of the functional arm. The reduction of valve control makes prosthetic training and use easier.

Recently hybrid systems came into use because electric power proved superior to pneumatic power for pronation and supination and gripping, whereas Co₂ is still necessary for locking the elbow and the shoulder joint. The accumulator can be recharged daily at a plug socket, the CO₂ container need only be refilled after one or two weeks ensuring more independence for the disabled. The advantage of such a prosthesis is the better appearance in public combined with a certain functional use.

However only intensive foot training without prostheses provides independence in daily activities, because even sophisticated prosthetic systems cannot make up completely for body loss.