A - D | E - H | I - L | M - P | Q - T | U - Z |

Radiculopathy: A pathological condition of a spinal nerve or nerve root.

Reciprocal Inhibition: A contraction of the agonist, which causes a relaxation in the antagonist. 

Reflex: An involuntary response to an exciting stimulus.

Reflex Arc: The neural pathway of a reflex. This arc consists of a sensory neuron, which carries the stimulus to the central nervous system, and a motor neuron, which carries the message of the central nervous system to the effector that carries out the message.

Reinforcement Procedures: Techniques applied by the examiner that can help to achieve a reflex response.

Rigidity: An increase in muscle tone that is not velocity dependent (i.e., changes in velocity do not increase/decrease muscle tone).

Spasticity: An increase in muscle tone that is velocity dependent; as the velocity of passive movement increases so does the muscle tone.

Spinal Cord Injury (SCI): An injury to the spinal cord, which causes neurological deficits.

Supine: A position in which the subject is lying on his or her back.

Traction: The separation of two surfaces by means of a force that is perpendicular to the concave surface.

Traumatic Brain Injury (TBI): An acquired neurological disorder caused by a traumatic force directed at the brain. Symptoms can range from mild to severe and can include memory loss, confusion, behavioral problems, and/or gait disturbances. 

Tumor: An abnormal growth, which can be benign or malignant in nature.