Research Focus: Neural Control of Human Movement

The Neurophysiology Laboratory focusses on identifying how the nervous system controls human movement. Within this broad area of investigation, research is divided into two main categories:

  1. How sensory feedback contributes to movement control, including
    • The role of reflexes in neural control of movements such as walking and grasping
    • The importance of feedback from sensory receptors in the skin
  2. Using electrical stimulation to generate contractions of human muscle. This work has relevance both for understanding how the nervous system controls movement but also for using electrical stimulation for rehabilitation for persons with movement disorders.

How intrinsic properties of neurons within the spinal cord play a role in helping to shape motor output, including

    • The extent to which such intrinsic neuronal properties contribute to normal voluntary contractions and "abnormal" contractions such as those during muscle cramps, spasms and spasticity.
    • Whether activating these spinal neurons may be useful clinically for functional electrical stimulation (FES) of muscle to help restore movement and overcome the muscle wasting that results from disuse.
  • Current findings show that:
    • when electrical stimulation is applied over human muscle, large contractions develop which are not due to the direct activation of the muscle beneath the stimulating electrodes.
    • They result from the “reflex” activation of neurons within the spinal cord, probably involving plateau potentials in the spinal neurons.
    • This suggests that human spinal neurons may play a very active role in helping to shape motor output.

Other Research

Nerve conduction velocity in an elephant is measured. See story.

Electrically stimulating reflex pathways in the spinal cord holds new hope in preventing muscle atrophy. See story.

Recently Presented Posters

SCAPPS 2005 Intensity of an auditory "go" signal alters sprint start reaction time.
Neuroscience 2005 Motor Unit Recruitment During Tetanic Electrical Stimulation.
Neuroscience 2005 Reflex connections from the lower limb to the erector spinae muscle in humans.
Neuroscience 2007 Evidence for persistent inward currents in human motor neurons during low intensity electrical stimulation: Asynchronous motor unit firing.
Neuroscience 2007 Diurnal changes in plantar flexion torque and measures of cortical and spinal excitability: influence of chronotype.
Neuroscience 2007 Electrical stimulation applied over the nerve versus over the muscle uses different mechanisms to evoke muscle contractions.