Responses of human muscle spindle afferents during isotonic position holding and active movements

Brain Res. 1990 May 7;515(1-2):181-6. doi: 10.1016/0006-8993(90)90594-2.


Discharge characteristics of muscle spindle primary afferents from human finger flexors were investigated during load-bearing isotonic position holding, and intentional shortening or lengthening contractions. During position holding, units mostly showed a negative relationship between muscle length and impulse rate, particularly when the load was small. When the load was increased, Ia-discharge rates increased more in the elongated than in the shortened muscle, and the inverse position response became less pronounced. During active lengthening contractions, a stretch response pattern was sometimes absent or could be abolished by increasing the load.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Female
  • Fingers / physiology*
  • Humans
  • Male
  • Movement / physiology*
  • Muscles / innervation*
  • Muscles / physiology
  • Neurons, Afferent / physiology*