This research (1) builds on 2 of our previous studies that have investigated how chiropractic care impacts brain function, in particular, brain changes associated with the control of arm and leg muscles. (2, 3)

These studies looked at an aspect of brain function called the cortical silent period (CSP), which is one of the mechanisms the brain uses to help control movement, like the way we use the gas pedal or brake pedal to help control the movement in our car. In our previous studies, we showed that through adjusting vertebral subluxations, there was a change in the cortical silent period following chiropractic care. This finding supports the theory that correcting vertebral subluxations causes neuroplastic brain changes that alter the way our brain perceives sensory information and controls bodily movement. (4-7)

Based on the past 20 years of work by one of our collaborators, Prof Türker, we suspected that the conventional understanding in the neuroscience community of what the CSP actually is, may be incorrect. Traditionally, the CSP is thought to reflect an inhibitory event (pushing the brake pedal), but we thought that it may have an excitatory component (pressing the gas pedal). So, we conducted this study in order to figure out what the change in CSP after an adjustment really means. What we found was that the CSP does appear to have an excitatory component and the mechanisms underlying the CSP involve several different neural networks and are more complex than is often thought. These findings help us to better understand how chiropractic care really impacts brain function and motor control.

At the CCR we are committed to the pursuit of excellence and endeavour to push the boundaries of science and not accept the status quo. That is exactly why we did this latest study. There is SO much more that we need to learn to understand neuroplasticity and the impact that chiropractic care may have on it and we are proud to be at the forefront of this quest for knowledge!

This newly published study was funded by the Australian Spinal Research Foundation, the New Zealand College of Chiropractic and the New Zealand College of Chiropractic Research Supporters Programme, Koç University School of Medicine, Istanbul, Turkey, and the Scientific and Technological Research Council of Turkey (TÜBİTAK).


  1. Ozyurt MG, Haavik H, Nedergaard RW, Topkara B, Şenocak BS, Göztepe MB, Niazi IK, Turker K. Transcranial magnetic stimulation induced early silent period and rebound activity re-examined. Plos One. 2019;14(12), e0225535.
  2. Haavik H, Niazi IK, Jochumsen M, Ugincius P, Sebik O, Yilmaz G, et al. Chiropractic spinal manipulation alters TMS induced I-wave excitability and shortens the cortical silent period. J Electromyogr Kinesiol. 2018;42:24-35.
  3. Taylor HH, Murphy B. Altered sensorimotor integration with cervical spine manipulation. J Manipulative Physiol Ther. 2008;31(2):115-26.
  4. Daligadu J, Haavik H, Yielder PC, Baarbe J, Murphy B. Alterations in cortical and cerebellar motor processing in subclinical neck pain patients following spinal manipulation. J Manipulative Physiol Ther. 2013;36(8):527-37.
  5. Haavik H, Murphy B. The role of spinal manipulation in addressing disordered sensorimotor integration and altered motor control. J Electromyogr Kinesiol. 2012;22(5):768-76.
  6. Haavik Taylor H, Murphy B. Cervical spine manipulation alters sensorimotor integration: A somatosensory evoked potential study. Clin Neurophysiol. 2007;118(2):391-402.
  7. Lelic D, Niazi IK, Holt K, Jochumsen M, Dremstrup K, Yielder P, et al. Manipulation of Dysfunctional Spinal Joints Affects Sensorimotor Integration in the Prefrontal Cortex: A Brain Source Localization Study. Neural plasticity. 2016;2016:3704964.