The human stretch reflex and the motor cortex

Trends Neurosci. 1991 Mar;14(3):87-91. doi: 10.1016/0166-2236(91)90064-2.


The spinal stretch reflex, exemplified by the tendon jerk, appears to be less important in humans than a delayed 'long-latency' response. This is easily observed when muscles of the hand are stretched while they are already contracting voluntarily. On limited evidence, many have long held that the delayed response is a transcortical reflex and have tended to neglect alternative possibilities, particularly that it might be a spinal reflex dependent upon slow afferents. New experiments have now eliminated the alternatives, leaving the transcortical hypothesis in command of the field.

Publication types

  • Review

MeSH terms

  • Animals
  • Cats
  • Electromyography
  • Humans
  • Motor Cortex / physiology*
  • Muscle Contraction / physiology
  • Reaction Time
  • Reflex, Stretch / physiology*