The specialty field of orthotics focuses on the design, creation, and use of orthoses, which are devices used externally to modify the body’s structural and functional characteristics and capabilities. They are intended to improve the person’s ability to move and function. Specifically, orthoses can help control or restrict movement in a joint, extremity, or other body region; reduce weight bearing for a certain part of the body; support body parts following cast removal; or correct the shape of certain body structures (such as the spine). To optimize the fit and function of an orthotic device, the orthosis often is customized to the individual using plaster of Paris molds or, more recently, computerized 3D printing. However, there are several types of orthotic devices that are available for over-the-counter purchase (e.g., shoe inserts). They are typically constructed using thermoplastics, carbon fibre, metal, elastic, EVA, and/or fabric. Healthcare professionals specializing in the field of orthotics are known as orthotists. They work under the prescription of a licensed healthcare provider, such as a physician. While physical therapists typically are unable to prescribe orthoses in the U.S., they can develop plans of care to help patients fitted with orthoses achieve maximum function using the device.