The Anatomy of a Leg Prosthesis

The Anatomy of a Leg Prosthesis

An artificial limb, or prosthesis, is a system of components that come together to perform the many functions of the amputated limb. While it can take many parts to construct some of the most advanced prosthetic limbs, all prostheses have several components in common—the prosthesis, a socket and attachment mechanism, and a control system.

Prosthetic Limb

Function plays a major role in the construction of a prosthesis—everything from specific activities to the location of an amputation comes into play to dictate how a prosthesis must be built. For a leg prosthesis, the major concerns are the structural requirements of bearing not only one’s body weight, but also the forces of movement. Prosthetics materials must balance strength and durability with comfort and weight to ensure the prosthesis does the job properly and is something that can be worn all day long.

Socket and Attachment Mechanism

Attaching to the residual limb can be a complex undertaking, depending on the site of your amputation, but it is important to find the best system in order to ensure a prosthesis delivers maximum comfort and effectiveness. There are two portions of this system—the socket, which attaches to the residual limb, and the attachment mechanism. To create the socket, a prosthetist makes a plaster cast, laser scan, or some other model of the residual limb and then uses that model to mold the socket.  From there, a system to secure the socket to the residual limb is needed. Everything from suction and pins, to straps and harnesses come together to ensure the limb fits snugly with maximum control.

Control system

Something most people don’t consider is how complex our natural limbs actually are. Unfortunately, this makes the development of control systems a difficult undertaking. In the past, prosthetic legs were little more than the stereotypical “peg leg,” but now there are much more sophisticated prostheses, which offer electrically-controlled joints, electrodes to sense impulses in the muscles of the residual limb, and even Smartphone integration.

As you can see, these three systems can be relatively simple or quite complex all on their own, but every prosthesis is constructed out of some form of all three systems. Each system plays a vital role and must be carefully considered to ensure you can meet the level of activity you desire, without sacrificing the all-day comfort you deserve.