An Orthosis is a device which is used to correct a specific deformity or injury. Orthotics are manufactured by an Orthotist. These can be made from numerous materials, Plaster of Paris, metals, plastic, fibreglass, leather, textile, or combinations of these. Often pre-fabricated components are used to enable better functionality. Examples of Orthoses are crutches, innersoles (Foot Orthotics), built-up shoes, braces, wheelchairs and elastic stockings.