Stretch Reflexes: Example in Cats

Image Reference: Prochazka, A, Hullinger M., Trend, P and Durmuller, N. (1988) Dynamic and Static Fusimotor Set in Various Behavioural Contexts. In: Hník P, Soukup T, Vejsada R, Zelená J (eds) Mechanoreceptors. Development, structure and function, Plenum Press, New York, pp. 422.

Stretching in Cats

Fusimotor set summary. The specific balance of static and dynamic fusimotor activity under different behavioural conditions is shown.

  1. At rest: no fusimotor activity.
  2. Preparation for movement: ‘wind-up’ of fusimotor drive, predominantly static in type.
  3. Slow walking: low level static fusimotor action.
  4. Fast walking: further ‘wind-up’ of static activity with additional a-linked dynamic fusimotor action.
  5. Imposed movements: ‘switch’ from predominant static fusimotor activity to dynamic drive.
  6. Difficult, unpredictable or novel motor tasks: reintroduction of static fusimotor activity to a greater (beam and ladder walking) or lesser (paw shakes) extent.