The Bekhterev-Mendel reflex, also known as the Mendel reflex or Mendel-Bekhterev reflex, is a clinical sign

Medical sign

A medical sign is an objective indication of some medical fact or characteristic that may be detected by a physician during a physical examination of a patient....

 found in patients with pyramidal tract lesions

Upper motor neurone lesion

An upper motor neuron lesion is a lesion of the neural pathway above the anterior horn cell or motor nuclei of the cranial nerves. This is in contrast to a lower motor neuron lesion, which affects nerve fibers traveling from the anterior horn of the spinal cord to the relevant muscle.Upper motor...

. Percussion

Percussion (medicine)

Percussion is a method of tapping on a surface to determine the underlying structure, and is used in clinical examinations to assess the condition of the thorax or abdomen. It is one of the four methods of clinical examination, together with inspection, palpation and auscultation...

 of the dorsum

Dorsum (biology)

In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...

 of the foot causes flexion

Flexion

In anatomy, flexion is a position that is made possible by the joint angle decreasing. The skeletal and muscular systems work together to move the joint into a "flexed" position. For example the elbow is flexed when the hand is brought closer to the shoulder...

, or downward movement, of the 2nd to the 5th toes in patients with pyramidal tract lesions, whereas percussion of the dorsum of the foot in normal patients causes extension

Extension (kinesiology)

In kinesiology, extension is a movement of a joint that results in increased angle between two bones or body surfaces at a joint. Extension usually results in straightening of the bones or body surfaces involved. For example, extension is produced by extending the flexed elbow. Straightening of...

 of the toes.

It is analogous to the Bekhterev-Jacobsohn reflex

Bekhterev-Jacobsohn reflex

The Bekhterev-Jacobsohn reflex, or Jacobsohn's finger flexion sign, is a clinical sign found in patients with pyramidal tract lesions of the upper limb...

 in the upper limb.

The reflex is named after Vladimir Bekhterev

Vladimir Bekhterev

Vladimir Mikhailovich Bekhterev was a Russian Neurologist and the Father of Objective Psychology. He is best known for noting the role of the hippocampus in memory, his study of reflexes, and Bekhterev’s Disease...

 and Kurt Mendel

Kurt Mendel

Kurt Mendel was a German neurologist who was a native of Berlin. In 1897 he received his doctorate from Kiel, and in 1899 went to work at the policlinic of Emanuel Mendel in Berlin...

.