The Types of Artificial Limbs and How They Work

Written by Metro Dental. Posted in Lace-up ankle orthosis, Orthotist wausau, Walking boots

Custom orthotics

If you have the good fortune to still have all your limbs, you probably never think about limb loss and take your arms and legs mostly for granted. All around us every day, however, limb loss is a reality.

So much so that experts estimate that by 2050, 3.6 million people in America will be living without a limb. Already, about 185,000 a year have an amputation, mostly commonly from either vascular disease or trauma. The least common reason for an amputation is from a congenital birth defect, which still affects one out of every 2,000 babies born.

As grim as this picture is, orthotic services in the United States have never been better. There are currently more than 3,000 care centers in America that work with limb loss, providing everything from prosthetic services to physical therapy for enhancing mobility, to whatever items might be needed to assist mobility: such from full artificial limbs to a back brace.

And for people who are living with limb loss, the choice of prosthetic limbs today is much more encouraging than it was only a few decades ago. Some orthotics now look and work so well that it is virtually impossible to tell they are artificial.

There are four primary kinds of prosthetics. The transtibial prosthetic is a lower leg that attaches to an intact upper leg. The transfemoral is both an upper and lower leg, including a knee. Arm prosthetics for below the elbow are called transradial, while upper and lower arms, including an elbow, are known as transhumeral prosthetics.

Many of these prosthetics can now be made into custom orthotics that meet the needs of every unique individual?s situation. Some prosthetics are crafted with cosmetics most in mind; that is, a natural appearance is key. This is especially true for artificial hands, for example. Others are built largely with their practical use in mind.

The limb itself needs to be lightweight but very strong, because it is more difficult to move a prosthetic than a natural limb. Many are made of carbon fiber covered with foam or plastic. The most important element of comfort when it comes to prosthetics is usually the socket, which is the point where the artificial limb connects with the remaining natural limb.

The fit of the socket needs to be perfect so that it does not damage the remaining limb or cause too much wear and tear on existing muscles. Those suffering limb loss will need to wear orthotics for the rest of their lives, so the new limb must be custom built, properly fitted, and made as comfortable as possible.

Another important consideration for orthotics is the control system. We move our natural limbs by sending signals to the muscles from our brain, via our own bodies? nervous system. How does it work with an artificial limb?

Some artificial limbs use mechanical cables which can be operated by the wearer in some way, often with another hand or shoulder. Some prosthetics, such as lower legs, may use just gravity and the user?s upper leg muscles to do their work. And some new artificial limbs have rechargeable batteries and are controlled electrically.

The newest and most sophisticated of all artificial limbs use electrodes to sense when the wearer?s residual natural limb is making a movement. Those electrodes then communicate with electric motors in the artificial limb, which moves much as a limb naturally would.

These newest prosthetics are known as myoelectric prosthetics. They feel the most natural to use because they respond in much the same way as any natural limb does. In the future, as prices come down and technology continues to advance, it is likely that these myolectrics will be the primary form of prosthetics, particularly for arms and hands.

The most important issue for anyone suffering from limb loss is finding the best prosthesis for their needs and budget, from a good prosthetist, and making a new limb as comfortable and useful as possible.

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