How Prosthetic Limbs Work

Dwayne LongProsthetic Limbs Work

Not everybody is endowed with a perfect body and we fret over that fact. But for a few of us, we aren’t even granted a complete body. Imagine having to give up a limb due to some reason and still having the need to continue living life and not give up as we have come here to do much more than what’s “needed”. That’s the spirit with which an amputee or limbless person wakes up every morning. But thankfully, technology and mechanics have tried really hard to fill up their bodily void, if not the mental setback. Prosthetic limbs can be called a boon for those who are missing a part of their body.

Design

Design of any prosthetic limb solely depends on the usage decided for it due to need of the patient and site of their amputation. A cosmesis is a prosthetic limb designed majorly for cosmetic purposes and not much attention is paid to the control. Efforts have been made to make the limb very similar to the user’s original body part. The patient’s skin tone can be duplicated using modern plastics and pigments. Details can be replicated to the ‘T’ including hair and fingerprints.

While looking at limbs which are more functional than aesthetic, one might go for a prosthetic arm which is shaped like a pincer and helps the patient grab things and do other work. A covering looking like a hand shaped glove can make it look close to a hand.

Control

Control of the prosthetic limb is done via different methods. One could be a body-powered limb which is connected to another part of the body by making use of cables which is attached to another healthy and strong body part which works the way a natural body part should. The limb can be controlled by another healthy muscle analogous to how a foot is used to strike the pedal to apply brakes in a car. Another way of control could be attained by using limbs powered by motors. Use of switches or buttons help the patient to use the limb in the way they desire for the task to be performed. Different tasks which are done using a hand or arm are imitated and duplicated by using sequence of pressing the buttons and switches in the order which lets the task be done. Some patients do not have to amputate an entire limb or they might have lost only a portion during an accident. In such cases, the residual part of the muscles can be used by the patient t control the prosthetic limb. Muscles while contracting generate electrical signals which can be read by electrodes measuring muscle movements. These prosthetic limbs are called Myoelectric and are a little similar in the way switch control prosthetic limbs work with the same working principle. A trans humeral prosthetic limb contains many joints and can be used using a sequence to move joints in a certain order for the action.