A prosthesis is “an artificial device to replace or augment a missing or impaired part of the body” (https://www.merriam-webster.com/dictionary/prosthesis). Prostheses have been developed for body parts including legs, arms, eyes, ears, teeth, portions of the skull, and nerves. A variety of designs exist for each prosthetic body part to enhance independence and mobility.
Prostheses are commonly used to replace amputated arms or legs. Limb amputation can be in response to injury, cancer or other diseases, or congenital anomalies.
For the lower limb, two general categories of prosthesis exist. People with below the knee amputations (BKA) require a portion of the lower leg, ankle joint, and foot replaced. People with above the knee amputations (TKAs) also require a portion of the upper limb and the knee joint. The type of prosthesis best suited for an individual depends on the location and extent of the person’s amputation as well as the person’s activity level and insurance provider. Prostheses are made from wood, polymers, light-weight metals, plastics, and carbon-fiber composites and are tailored for a variety of different needs. Prostheses may be functional or cosmetic. An upper limb prosthesis may terminate in an artificial hand or a hook. Silicone and PVC have been used to create prosthetic hands that look like real hands.
Advanced prostheses have been developed that include sensors, motors, and microprocessor controls. Lower limb prostheses of this type permit complex coordinated body movements. Advanced prostheses have even been surgically integrated into the nervous system to detect muscular contractions signals and use them to control a prosthetic arm.
