Orthotic devices are classified into four areas of the body according to the international classification system (ICS):
Orthosis are also classified by function: paralysis orthosis and relief orthosis.
Under the International Standard terminology, orthosis are classified by an acronym describing the anatomical joints they support. Some examples include: KAFO, or knee-ankle-foot orthosis, which span the knee, ankle, and foot; TLSO, or Thoraco-lumbo-sacral orthosis, supporting the thoracic, lumbar and sacral regions of the spine. Use of the International Standard is promoted as to reduce the widespread variation in the description of orthosis, which is often a barrier to the interpretation of research studies. Orthosis are offered as: