Effects of proprioceptive neuromuscular facilitation on the initiation of voluntary movement and motor evoked potentials in upper limb muscles

Hum Mov Sci. 2002 Apr;21(1):101-13. doi: 10.1016/s0167-9457(01)00057-4.

Abstract

To better understand the mechanisms behind proprioceptive neuromuscular facilitation (PNF), an important method in motor rehabilitation, we investigated the effects of assuming a PNF posture relative to a neutral posture on the initiation of voluntary movement (Experiment 1) and the excitability of the motor cortex (Experiment 2) using a wrist extension task. The initiation of voluntary wrist movement was operationalized in terms of the electromyographic reaction time (EMG-RT), and the excitability of the motor cortex in terms of motor evoked potentials (MEPs). Compared to the neutral position, we found that (1) the facilitation position changed the muscle discharge order enhancing the movement efficiency of the joint, (2) the facilitation position led to a reduction in EMG-RT, the magnitude of which depended on the proximity of the muscle to the movement joint, and (3) MEP amplitude increased and MEP latency decreased in the facilitation position as a function of the proximity of the muscle to the joint. These findings corroborate the presumed effects of PNF and provide insights into the neurophysiological mechanisms underlying the PNF method.

MeSH terms

  • Adult
  • Arm / innervation*
  • Electromyography
  • Evoked Potentials, Motor / physiology*
  • Female
  • Humans
  • Joints / innervation
  • Male
  • Motor Cortex / physiology
  • Motor Skills / physiology*
  • Muscle, Skeletal / innervation*
  • Neuromuscular Junction / physiology*
  • Proprioception / physiology*
  • Pyramidal Tracts / physiology
  • Reaction Time / physiology