ARTIFICIAL LIMBS FOR DISARTICULATION THROUGH THE SHOULDER JOINT AND AMPUTATION THROUGH THE DELTOID MUSCLE

So far as function is concerned these operations are identical; a short arm stump is incapable of transmitting movements to the socket of the artificial limb.

That is to say, our appliance will be a purely passive one, and at the present time it is useless to attempt to make any sort of worker's arm. We must aim simply at supplying a limb which imitates the external shape of the arm, with an elbow joint which can be locked with a ratchet. At most it is possible by a movement of the opposite shoulder to work an automatic thumb by means of a cord, as a rule, however, a simple spring thumb is preferred.

Nothing need be added to what has been said in the previous chapter about the elbow joint or the hand.

In the fitting of an attachment over the shoulder the amputation through the deltoid presents an actual advantage. For in this case the shape of the point of the shoulder is preserved, and the attachment carried out as described on pages 87 and 130 fixes the appliance very securely.

If the entire humerus has been removed a very extensive enclosure of the front and back of the chest is essential and in order that the axilla may be in close contact with the top of the limb it is a good thing to stretch across this space a layer of some firm material.

These appliances can be used to steady a piece of paper upon which the patient is writing, to carry a parcel which is not too heavy with the elbow flexed, to grip an article with the thumb. A workman who is being re-educated for some occupation which is possible for a one-armed man, will usually—unless he is going out for pleasure—leave his artificial arm at home in the cupboard.