Brain's reflex is the extension of a

hemiplegic Hemiparesis, also called unilateral paresis, is the weakness of one entire side of the body ('' hemi-'' means "half"). Hemiplegia, in its most severe form, is the complete paralysis of one entire side of the body. Either hemiparesis or hemiplegia ...

flexed arm when a

quadrupedal Quadrupedalism is a form of Animal locomotion, locomotion in which animals have four legs that are used to weight-bearing, bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four l ...

posture is assumed by a human subject. It was first described by Russell Brain, a British

neurologist Neurology (from , "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the nervous system, which comprises the brain, the ...

.''Encyclopædia Britannica''

References

Reflexes {{med-sign-stub