Training-induced adaptive plasticity in human somatosensory reflex pathways

J Appl Physiol (1985). 2006 Dec;101(6):1783-94. doi: 10.1152/japplphysiol.00540.2006. Epub 2006 Jun 29.


This paper reviews evidence supporting adaptive plasticity in muscle and cutaneous afferent reflex pathways induced by training and rehabilitative interventions. The perspective is advanced that the behavioral and functional relevance of any intervention and the reflex pathway under study should be considered when evaluating both adaptation and transfer. A cornerstone of this concept can be found in acute task-dependent reflex modulation. Because the nervous system allows the expression of a given reflex according to the motor task, an attempt to evaluate the training adaptation should also be evoked under the same conditions as training bearing in mind the functional role of the pathway under study. Within this framework, considerable evidence supports extensive adaptive plasticity in human muscle afferent pathways in the form of operant conditioning, strength training, skill training, and locomotor training or retraining. Directly comparable evidence for chronic adaptation in cutaneous reflex pathways is lacking. However, activity-dependent plasticity in cutaneous pathways is documented particularly in approaches to neurological rehabilitation. Overall, the adaptive range for human muscle afferent reflexes appears bidirectional (that is, increased or reduced amplitudes) and on the order of 25-50%. The adaptive range for cutaneous pathways is currently uncertain.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Action Potentials / physiology
  • Adaptation, Physiological / physiology
  • Afferent Pathways / physiology*
  • Animals
  • Exercise / physiology*
  • Humans
  • Motor Neurons / physiology
  • Muscle Contraction / physiology
  • Muscle, Skeletal / physiology*
  • Neuronal Plasticity / physiology*
  • Physical Fitness / physiology*
  • Reflex / physiology*
  • Somatosensory Cortex / physiology*