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(or″thō-rē″ō-vī′rŭs) [ortho- + reovirus] A genus of viruses of the family Reoviridae, occasionally associated with respiratory and digestive diseases. SEE: Reoviridae.


(or-thō′sĭs, or-thō′sēz″) pl. orthoses [Gr. orthōsis, guidance, straightening] Any of a class of external orthopedic appliances, braces, or splints applied to the body to stabilize, control, limit, or immobilize a body part, prevent deformity, protect against injury, or assist with function. Orthosess range from arm slings to corsets and finger splints. They may be made from a variety of materials, including rubber, rubber synthetics, leather, canvas, and plastic. orthotic (or-thot′ik), adj.

ankle-foot o. ABBR: AFO. An orthosis to control, limit, or assist foot and ankle motion and provide leg support. Typically, orthotics are made of lightweight materials such as thermoplastics. SEE: illus.





PATIENT CARE: A variety of ankle-foot orthoses are used. In the treatment of Achilles' tendon rupture, e.g., the orthosis holds the foot at a right angle to the horizontal plane of the body, in plantar flexion.

balanced forearm o. Mobile arm support.

halo vest o. Halo vest.

spinal o. An orthosis applied to the back (and often encircling the trunk) that limits the movement of the vertebrae, alleviates pain, or unloads mechanical stress; a back brace.

thoracolumbar o. An orthosis to stabilize the lower back (the lower portion of the thoracic spine and all of the lumbar vertebral bodies). It is used to treat diseases and conditions such as idiopathic scoliosis (in children and adolescents) or low back vertebral fracture.

wrist-driven hand o. ABBR: WDHO. An orthosis that uses the muscles of the wrist, esp. the extensor muscles, to drive the fingers together into a grasping motion. It can be used by people with paralysis of the hand to improve the ability to hold on to and release objects.

wrist-driven wrist-hand o. ABBR: WDWHO. An orthosis used for functional grasp by people with C6 tetraplegia. SEE: tenodesis (2); universal cuff.


(or″thŏ-stat′ĭk) [ortho- + static] Pert. to or caused by an erect position.

orthostatic intolerance

Loss of consciousness, near fainting, or light-headedness occurring when a person stands up from a seated or resting position. It is caused by insufficient blood flow to the brain, typically brought on by inability to raise blood pressure during changes in posture.

orthostatic vital signs determination

The measurement of patient blood pressure and pulse rate, first in the supine, then in the sitting, and finally in the standing position. A significant change in both ...

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