Most of the time, if you break a bone or sprain an ankle, you go to the doctor. They’ll tell you to ice it and will sometimes put it in a cast. But what happens if you lose your leg or arm? Sometimes in major accidents or as a result of a disease like osteosarcoma (a type of cancer) patients can be left without a major limb, like their leg or arm. How do they go about their regular lives after that? The answer is prosthetics. A prosthetic is a man-made substitute for a body part. They can be anything from a fake leg to a fake hand to a fake eye. Some prosthetics can be removable, like with a leg or hand. Others are permanent, like hip replacements.

Permanent prosthetics, like hip replacements, typically require some sort of surgery to implant the prosthetic and another surgery if there is any reason to remove it. Removable prosthetics have varying degrees of complexity depending on how much of the arm or leg they are replacing. For example, a prosthetic that just needs to simulate the motion of the hand is simpler than something that needs to replace the whole entire arm. Typically, patients have a sleeve they put over the limb and they pull on the prosthetic, almost like a sock. Of course, there are other ways to attach the prosthetic depending on how the prosthetic works, but this is the way most simple prosthetics are attached.

When they create prosthetics, engineers have to consider a lot of different factors. First, they make a mold of the patient’s limb so they have something to base the creation of the prosthetic off of. The prosthetic itself can be made of many different things. Some prosthetics are designed for appearances. Designers do their best to match the patient’s skin color in the plastic. Other prosthetics are designed with functionality in mind and to give the patient as much control as possible. For example, some hand prosthetics are detachable with various shapes, such as a hook for grabbing things. Other body prosthetics (legs or arms) are controlled with cables attached to healthy muscles or even with electricity.