The Anatomy of Prostheses: How Prosthetic Limbs Work

Today’s prosthetic limbs are so advanced that some can even restore function. It’s hard to remember that veterans from the 19th century (or earlier) used prostheses that were heavy, stiff, and cumbersome. To understand how prosthetic limbs work today, it helps to understand the different components of prostheses.

The Appearance of Prostheses

The parts of prostheses depend on what kind of prosthesis you have. For example, there are cosmetic prostheses that are meant to mimic the natural limb. Typically, these prostheses get their shape from soft foam and have a synthetic skin covering. These days, you can even get prostheses with details like freckles, fingerprints, or nails that you can paint with nail polish.

Alternatively, you may prefer prostheses that favor function over appearance. They don’t have a synthetic skin covering, so plastic and metal parts are exposed. These types of prostheses may allow more agility or bounce, and may be helpful for sports. Otherwise, you may prefer these types of prostheses simply because they tend to be less expensive than cosmetic prostheses.

Some prostheses may come with additional appendages, like fingers on the hand. They may also have functional joints, like an ankle, elbow, or wrist. While some prostheses have natural-looking hands or feet, a prosthesis can instead have functional tools. For example, alternatives to a traditional hand include hooks, grips, or even web-like tools that can dribble a basketball.

How Prosthetic Limbs Work

In order to improve quality of life for veterans and others who need prostheses, an artificial limb has to fit right and function well. There are a number of parts of prostheses that ensure a good fit.

For starters, prostheses have a socket to attach to your natural limb. Think of it like a bowl that holds the residual limb. Within that socket is a suspension system with a vacuum pump, which helps to remove air and create suction. This helps hold the prosthesis in place. Additionally, some models secure the limb and prosthesis using a locking pin or straps.

Next, there’s the interface. This is the surface between your skin and the prosthetic socket. Typically, they involve some type of liner or cushion. This helps to distribute pressure evenly and protect the skin. These may vary depending on the needs. For example, an athlete with a leg prosthesis may need more elaborate lining to help bear weight and reduce pain during high-impact activity.

Making a Prosthesis Work for You

This is just a brief overview of prosthetic limbs, and there are a lot of different parts that make prostheses work. Getting all of them to work just right takes patience. Most likely, you'll have several visits to the prosthetist to get the perfect fit. For example, pressure should be evenly distributed, and the prosthesis shouldn't be painful.

You may even have more than one prosthesis to help you transition from one activity to another. These days, whatever your civilian lifestyle, and whatever your needs, there's a prosthesis for you.